Academic literature on the topic 'Phased-array ultrasound transducer'
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Journal articles on the topic "Phased-array ultrasound transducer"
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Turnbull, Daniel H., and F. Stuart Foster. "Simulation of B-Scan Images from Two-Dimensional Transducer Arrays: Part Ii - Comparisons between Linear and Two-Dimensional Phased Arrays." Ultrasonic Imaging 14, no. 4 (1992): 344–53. http://dx.doi.org/10.1177/016173469201400402.
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Two-dimensional (2-D) arrays have been proposed as a solution to the degradation in medical ultrasound image quality occurring as a result of asymmetric focusing properties of linear phased array transducers. The 2-D phased transducer array is also capable of electronically steering the symmetrically focused ultrasound beam throughout a three-dimensional volume. In a companion paper the potential of 2-D transducer arrays for medical imaging has been investigated using simulated B-scan images. In this paper, the advantages of 2-D over linear transducer arrays is demonstrated by simulating images of spherical cysts embedded in a large scattering volume. The large elevation beamwidth in the nearfield of a 5 MHz linear phased transducer array results in a severe reduction in the image contrast measured between a 4 mm diameter cyst and the surrounding scattering media. By employing a 2-D array with symmetric focusing, the contrast between the cyst and surrounding scatterers is significantly improved. The use of additional elements in the elevation direction of a linear array is also investigated. In this case the additional elements are included only to focus, but not to steer the ultrasound beam. Using the contrast characteristics of a 4 mm diameter cyst, it is shown that relatively few elevation elements are required to significantly improve the nearfield imaging capability of the linear array.
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Gentry, Kenneth L., Nasheer Sachedina, and Stephen W. Smith. "Catheter Ultrasound Phased-Array Transducers for Thermal Ablation: A Feasibility Study." Ultrasonic Imaging 27, no. 2 (2005): 89–100. http://dx.doi.org/10.1177/016173460502700203.
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The feasibility of catheter single-element ultrasound transducers for cardiac ablation has been shown previously. We describe the design and testing of catheter-sized linear phased arrays transducers for ultrasound ablation. One array has 86 PZT-4 elements operating at 8 MHz and 5 MHz. The overall array size is 14.9 mm by 3.1 mm (10 Fr). The other array has 50 PZT-5 elements operating at 4 MHz and is 17 mm by 3.1 mm (10 Fr). In order to produce the intensity needed to create lesions in heart tissue, we modified a real-time, 3D scanner to produce 100 Vpp 256-cycle transmit pulses at a pulse repetition frequency of 14.1 kHz. This made it possible for the PZT-4 and PZT-5 transducers to produce ISPTA of 3.26 W/cm2 and 142 W/cm2, respectively. When driving the transducers at high duty factor, the transmit circuitry in the scanner was damaged. A mechanically-focused transducer with the same dimensions as the PZT-4 transducer was built. When transmitting continuously at 9 MHz, it produced an ISPTA of 29.3 W/cm2. This created a lesion 5 mm across and 5 mm deep in beef tissue while raising the focal temperature 23°C. Ablation is within the capabilities of a catheter phased array transducer integrated into a diagnostic ultrasound scanner.
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Wang, Hongliang, Jiao Qu, Xiangjun Wang, Changde He, and Chenyang Xue. "Investigation and Analysis of Ultrasound Imaging Based on Linear CMUT Array." International Journal of Pattern Recognition and Artificial Intelligence 33, no. 08 (2019): 1957004. http://dx.doi.org/10.1142/s0218001419570040.
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In the next generation of ultrasound imaging systems, Capacitive micromachined ultasonic transducer (CMUT) based on microelectromechanical systems (MEMS) is a promising research direction of transducers, which has wide application prospects. In this paper, based on the study of three imaging methods, including classical phased array (CPA) imaging, classical synthetic aperture (CSA) imaging and phased subarray (PSA) imaging, several different imaging schemes are designed for linear CMUT array, after that the performances of these imaging schemes are compared and analyzed. The effects of the three imaging methods are verified and analyzed based on the linear CMUT array. Through analysis, it is found that the image quality of the classical phased array imaging method is the best, the imaging quality of the above three imaging methods can be effectively improved by adopting the amplitude apodization and dynamic focusing method. The research results in this paper will provide theoretical basis and application reference for the design of ultrasonic imaging system based on linear CMUT array in the future.
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Ellingson, William A., J. Scott Steckenrider, and Thomas J. Meitzler. "Defect Detection in Ceramic Armor Using Phased Array Ultrasound." Advances in Science and Technology 65 (October 2010): 143–52. http://dx.doi.org/10.4028/www.scientific.net/ast.65.143.
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Monolithic ceramic tile is used as part of ceramic-composite armor. Rejection of individual tile that contain potential threat-defeat-reducing ―defects‖ must be accomplished in a fast and cost-effective manner. Water-immersion phased-array ultrasound using 10 MHz 128-element transducers sequenced at 32-elements has been demonstrated to quickly scan and detect 25-50 um known inclusion-type defects in individual 25 mm thick SiC tile. Further, use of similar phasedarray transducers and similar transducer-element activation sequences, has shown detection of intentional internal defects in tests of 40 cm square by 50 mm thick, multi-layered composite ceramic-armor specimens. Large changes in acoustic velocities of the various layered materials causes focusing issues of the ultrasonic wave. The use of various digital signal processing methods can be used to overcome some of these issues. The results show that use of phased array ultrasound can reliably be used for defect detection in either monolithic or composite ceramic-armor. The technology and various results are presented.
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Curley, Jonathan, Christian Renwick, and Venkat Mangunta. "Handheld Ultrasound Device Utilization in Extracorporeal Membrane Oxygenation Initiation." Journal of Cardiac Critical Care TSS 8 (October 24, 2024): 246–51. http://dx.doi.org/10.25259/jccc_41_2024.
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Ultrasound imaging is recommended to augment the initiation of extracorporeal membrane oxygenation (ECMO). Handheld ultrasound devices may serve as potential imaging tools, given the increasing image quality and ultrasound functionality in recent models. Specifically, dual transducer ultrasound devices that provide both a phased array and linear transducer on a single device may offer exceptional value to the intensivist or ECMO clinician. A description of the potential utility of incorporating dual transducer ultrasound devices into ECMO initiation and corresponding images depicting image quality and usage. The dual transducer ultrasound device may serve as a valuable clinical tool for the intensivist or ECMO clinician.
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Benkeser, P. J., L. A. Frizzell, K. B. Ocheltree, and C. A. Cain. "A Tapered Phased Array Ultrasound Transducer for Hyperthermia Treatment." IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 34, no. 4 (1987): 446–53. http://dx.doi.org/10.1109/t-uffc.1987.26965.
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Phipps, Marshal A., Thomas J. Manuel, Michelle K. Sigona, et al. "Image guidance and beam localization for transcranial focused ultrasound therapy." Journal of the Acoustical Society of America 152, no. 4 (2022): A154. http://dx.doi.org/10.1121/10.0015867.
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Therapeutic uses of transcranial focused ultrasound (tFUS) in the brain are being widely explored in both clinical and research settings from tissue destruction to blood brain barrier opening (BBBO) to neuromodulation. The appeal of tFUS is the ability to target structures throughout the brain with a millimeter scale focus. In order to understand the outcome of the treatment or experiment it is important to ensure the tFUS beam is targeted to and located at the region of interest. Image guidance allows for targeting of anatomical or functional structures within the brain. Here we present a targeting and localization scheme where optical tracking of the transducer is used to target the tFUS focus to a brain region within a previously acquired image and MR acoustic radiation force imaging is used to localize the beam in the brain to ensure the focus is at the target. By combining this targeting and localization scheme with a phased array transducer we are able to then steer the focus to ensure accurate sonications of specific brain regions using tFUS. This talk will discuss the application of this method to two different phased array transducers used for neuromodulation and BBBO in nonhuman primates.
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YANG, FENG-YI, TZU-JUNG MAO, YUNG-YAW CHEN, HSU CHANG, and WIN-LI LIN. "BEAM STEERING AND FOCUSING ABILITY OF A CONTACT ULTRASOUND TRANSDUCER FOR TRANSSKULL BRAIN DISEASE THERAPY." Biomedical Engineering: Applications, Basis and Communications 18, no. 06 (2006): 328–36. http://dx.doi.org/10.4015/s1016237206000488.
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This paper was to examine the steering and focusing ability of a contact hemispherical ultrasound transducer (80 mm radius of curvature, 160 mm diameter) for transskull brain diseases therapy without skull-specific aberration correction. This work employs a simulation program to investigate the effect of ultrasound transducer parameters on the steering and focusing ability for transskull therapy. The acoustic pressure distribution and the grating lobes in tissue were used to determine the steering and focusing ability of this transducer for a set of given conditions. Simulation results demonstrated that this hemispherical phased array transducer with low frequencies can steer a high-pressure focal zone in a large range within the brain. The peak and size of the high-pressure focal zone mainly depend on ultrasound frequency and the steering distance of the focal zone. By comparing the peak pressures between the focal zone and the grating lobe, 0.1 MHz transducer performed the desired results for large ranges (140 mm x-y direction and 138 mm z direction) of beam steering. The results reveal the feasibility of using a hemispherical phased array transducer with beam steering method at low frequency for brain diseases therapy within almost full range of the brain without performing a craniectomy.
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Liu, Li, and Jian Sun. "A Study of High Intensity Focusing Ultrasonic Transducer." Applied Mechanics and Materials 201-202 (October 2012): 20–23. http://dx.doi.org/10.4028/www.scientific.net/amm.201-202.20.
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High intensity focused ultrasound (HIFU) is the fourth brand-new and efficient means to cure tumour acknowledged by the medical field. Study of ultrasonic transducer is a core part of HIFU technique, In order to ensure reliability and safety of treatment, it is a key for HIFU technique to realize accurate focusing of ultrasonic energy. In the thesis, ultrasonic focusing method, studies of current situations of cell and multiplex array focusing transducers and their existing problems are illustrated based on analyzing challenges faced by HIFU treatment at present. This study suggested that phased array was theoretically easy for realizing accurate control of computer， however, unbeneficial factors and engineering technical problems still exist; How to promote intensity of the focal spot of cell array focusing transducer, enlarge scope of the focal area and improve control way of the focal spot was a bottleneck problem for publicizing and applying cell array focusing transducer and one of urgent research topics for ensuring curative effect of HIFU and avoiding heat damages.
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Hall, Timothy L., Jonathan R. Sukovich, Jon Cannata, J. Brian Fowlkes, and Zhen Xu. "Instrumentation for histotripsy ultrasound therapy: Evolution toward the clinic." Journal of the Acoustical Society of America 153, no. 3_supplement (2023): A138. http://dx.doi.org/10.1121/10.0018425.
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Histotripsy is a method of ultrasound therapy using very intense, focused sound fields to fragment tissue causing controlled and localized necrosis principally through mechanical actions of cavitation. Highly specialized instrumentation (transducers and electrical drivers) is required to produce these extreme sound fields for research into cavitation physics and therapeutic applications of histotripsy. This paper will describe the evolution of histotripsy instrumentation from the first devices up to the latest phased-array systems with hundreds of channels and transmit-receive capability. While early histotripsy systems used tone bursts generators with limited bandwidth (called “class-D” circuits) for transducer excitation, more recent ones are based on a switched inductor principle to produce shorter duration acoustic emissions. This method has been tested for peak excitation voltages up to 5 kV and 40 A in compact modular systems suitable for phased-arrays. Receive of acoustic signals by the therapeutic array for aberration correction and cavitation mapping is achieved by sensing current generated by the transducer greatly simplifying transmit-receive circuitry while maintaining very large dynamic range. A novel distributed architecture was developed for data handling and signal processing using off-the-shelf FPGA evaluation modules interfaced by ethernet. These latest features will be key to successful clinical translation and widespread adoption of histotripsy.
Dissertations / Theses on the topic "Phased-array ultrasound transducer"
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Qiu, Zhen. "Development of MRI-compatible transducer array for focused ultrasound surgery : the use of relaxor-based piezocrystals." Thesis, University of Dundee, 2014. https://discovery.dundee.ac.uk/en/studentTheses/572decc1-6a5b-420a-948d-e8f05740fcd5.
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Focused ultrasound surgery (FUS) is considered as a promising approach for treating cancer and other conditions and is gaining increasing interest. However, the limited availability of experimental ultrasound array sources and multichannel electronics able to drive them hinder the research into FUS system configurations for patient conditions such as breast cancer. The work in this dissertation explored the development of ultrasound arrays for MRI guided FUS, from the point of view of the potential piezoelectric material of choice. Two materials are of particular interests in this work: Binary (x)Pb(Mg1/3Nb2/3) O3 - (1-x)PbTiO3 (PMN-PT) piezocrystal, and newly specialized FUS material, PZ54 ceramic. A characterization methodology was developed to fully characterize the materials of choice, under ambient and extreme conditions relevant to FUS applications. Practicalities of adopting these materials into FUS were studied by using the characterized materials in designing and fabricating FUS arrays. A spherical, faceted array geometry inspired by the geodesic dome structure was proposed and implemented for the first time. Four bespoke devices, each with 96 individual elements, were implemented using PZ26 ceramic, PZ26 composite, PZ54 composite and PMN-PT composite materials, respectively for comparison. The arrays were connected to commercial electronics afterwards, to explore a prototyping route for connecting FUS devices and modular driving systems. It is concluded that PMN-PT piezocrystal and PZ54 ceramic material can offer excellent performance over conventional piezoelectric ceramics, although PMN-PT piezocrystal is sensitive to extreme conditions. The usable range of PMN-PT is suggested to be limited to 60°C in temperature and 10 MPa in pressure. However, PMN-PT piezocrystal could still be a potential alternative to conventional ceramics in FUS application if assisted with sufficient cooling circulation and bias field. The geodesic array geometry is also concluded to be able to achieve good focusing of ultrasound beam. With optimized phase control through multi-channel electronics, the focusing was improved with focusing gain up to about 30; the steering range of focus was explored within a volume of 5 x 5 x 10 mm3 beyond the array’s geometric focus, side lobes were limited to below the level of -9 dB in acoustic intensity. Larger numbers of individual controllable elements and alternative array designs will be explored in future to investigate application such as breast cancer treatment and potential pre-clinical trials.
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Althomali, Marwan Ahmad M. "Towards ultrasound computed tomography assessment of bone." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/119110/1/Marwan%20Ahmad%20M_Althomali_Thesis.pdf.
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This research is a proof of concept study, which focuses on the development and scientific validation of an ultrasound computed tomography (UCT) system with particular emphasis on imaging of bone replica models. Factors that were considered include quantification of complex structure along with tissue properties, such as bone stiffness and cortical shell thickness. For the first time, the concept of ultrasound computed tomography based finite element analysis (UCT-FEA) was investigated. Being non-invasive, non-destructive and non-ionizing, UCT has a significant potential to provide measurement of bone mechanical integrity and improve clinical assessment and management of osteoporosis.
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Yeh, Shochi. "Theoretical and experimental evaluation of radiation patterns generated by phased array ultrasound transducers with mechanical and electronic focussing /." Zürich, 1986. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=7962.
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Wang, Hong Han, and 王中翰. "Design and Calibration of Multi-channel Ultrasound Phased Array Transducer." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/rr7qhe.
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Lin, Jyun An, and 林俊安. "A 256-channel Ultrasound Phased Array System : Driving System and Transducer Design." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/76682659940939086650.
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碩士<br>長庚大學<br>電機工程學研究所<br>97<br>Focused ultrasound technology has confirmed that has the therapeutic effect for biological tissues, and temporarily opens the blood-brain barrier and does the functions of the brain to carry out local drug delivery in recent years. At present, for thermal ablation purpose, the frequency range of the driving system typically larger than 0.5 MHz for better tissue absorption and rapid temperature increase. However, the above frequency range encounters severe bone absorption and focal beam distortion to make the transcranial ultrasound therapy becomes difficult. The purpose of this study is to design a low-frequency 256-channel ultrasound phased array driving system for electronic phase shift to achieve a focus and real-time power monitoring function. The prototype system contains 256-channel driving module, multiple-channel power sensoring module, and one 256-channel hemispherical ultrasound phased array. Output power for each channel feed back to the control kernel by using a dual directional coupler circuit to let the control panel real-time monitor the power output. System performance testing includes output power testing, feedback power testing, acoustic pressure testing and ultrasound pressure measurements. Our results showed that the system can successfully generate ultrasonic focus, and the focal position can be steered by precisely controlling the relative phases of elements.
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Huang, Tzu-Ting, and 黃子庭. "Design of High-Intensity Focused Ultrasound Phased- Array Transducer for Essential Tremor Treatment." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/z8j8ut.
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碩士<br>國立交通大學<br>生醫工程研究所<br>107<br>In recent year, the increasing number of patients with essential tremor and the patients are also easily to suffer from Parkinson's disease at the same time. Besides, treatment options for patients with drug-resistant essential tremor(ET) are limited. The most recent advance in this area is magnetic resonance-guided focused ultrasound ( MRgFUS ), which is non-invasive, deep penetration, real-time monitoring and immediately benefits after the surgery. The currently ultrasonic therapy technology is a 1024-element hemispherical phased array high-intensity focused ultrasound. However, in this study, a 256-element ring-shaped phased array high-intensity focused ultrasound is investigated to test the feasibility of essential tremor surgery. In addition, urging to reduce the cost and complexity by reducing elements and channels.
In this study, not only Rayleigh integral and secondary source model but also the CT pictures of skull were used to improve the simulations. With the Matlab 2015a, the pressure field inside the brain are calculated. The frequency of 500 kHz, 600 kHz, 700 kHz, 750 kHz, 875 kHz, 1000 kHz and the height of the ring-shaped ultrasonic transducer 3 ~ 6 cm are simulated individually. In order to focus approximately the size of 4×10×6 mm3 on the ventral intermediate nucleus of the thalamus. The results show that at the frequency of 750 kHz and the height of 5 cm and 6 cm would perform achievable. Nonetheless, the focus range would be slightly larger than 10 mm but the intensity is sufficient.
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Shaffaf, Leila. "Development of a Phased Array Focused Ultrasound Transducer for Two-photon Microscopy Guided Neural Studies." Thesis, 2013. http://hdl.handle.net/1807/42918.
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Focused ultrasound combined with intravenously injected microbubbles is a promising non-invasive therapy capable of temporarily disrupting the blood-brain barrier for targeted drug delivery. Established in vivo experiments on rodent models combine focused ultrasound treatment with two-photon microscopy imaging to improve understanding of microvasculature response. A phased array, an advanced ultrasound therapy device, was successfully developed to improve pressure transmission in these experiments. An investigation of transducer sensitivity to setup equipment suggested modifications to setup procedures, for example recording objective position, may improve in situ pressure estimates. A ring array composed of 50 lateral mode elements, geometry determined by pressure field simulations, was successfully fabricated. Fibre optic hydrophone pressure field measurements confirmed the device had an appropriate focal size (0.7mm diameter x 4mm axial length) and reached therapeutic pressure levels (>0.5MPa). Ex vivo transcranial measurements demonstrated moderate focal correction and off-axis steering capabilities that may improve experimental throughput and target alignment.
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Chan, Hsin, and 詹訢. "Investigation of Spherical Phased-Array Ultrasound Transducer Using Pseudoinverse Technique for Brain Short-Time Hyperthermia." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5yck33.
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碩士<br>國立臺灣大學<br>醫學工程學研究所<br>107<br>Background: Brain metastasis tumors are one of the most significant issues in tumor therapy. Brain metastasis tumors are more frequent (>50%) than any other primary brain tumors and the appearance is about 25% of patients dying of cancer. In general, methods of dealing with these tumors include operation, chemotherapy and radiotherapy, but to some certain degree they are restricted to brain tumor’s conditions. According to previous research, brain metastasis tumors tend to remodeling with surrounding blood vessels and form blood-tumor barrier (BTB). Hyperthermia is found to locally enhance the permeability of BTB formed by brain metastasis tumor, which could benefit antitumor nanodrugs delivery. Researches show that focused ultrasound hyperthermia can enhance liposomal doxorubicin delivery and antitumor efficacy for brain metastasis of breast cancers to improve the mouse survival.
Purpose: Based on the array ultrasound transducer designed previously, in this study, we developed phase correction method to deal with skull aberration and to make the device actually applicable in clinic. Furthermore, we used new transducer parameters with smaller PZT element’s surface area and larger number of PZT elements to enlarge hyperthermia heating region by multi-foci pseudoinverse technique. When the tumors are not at the center of head, we must assure the multi-foci method still be able to create enough energy to complete the hyperthermia for clinical use.
Materials and Methods: In this study, we reconstructed the skull model by head CT images, calculating the pressure field in the brain for 1 MHz ultrasound by multi-layer second source wave model and Rayleigh Integral. According to bio-heat transfer equation, we simulated the temperature field and thermal dose distribution in the brain to evaluate the effect of hyperthermia. The skull aberration correction and multi-foci techniques are introduced to these simulations.
Results: The skull aberration correction technique can improve the focusing, producing more precise and accurate focal spots with new transducer parameters. In multi-foci technique, mode 1 (for multi-foci at (2,0,0)、(-2,0,0)) and mode 2 (for multi-foci at (0,2,0)、(0,-2,0)) can create an effective large hyperthermia region. In the case of switching mode 1 and mode 2 (switching rate at 5 Hz) with intensity limited by 150 W cm-2 for 180 seconds, it can create a region of 7 x 6 x 11 mm3 higher than 41 ℃ and the maximum of temperature lower than 45 ℃, thermal dose beneath the brain tolerance limit. For the cases of tumors not located at the center of head, the multi-foci technique can still produce effective heating region to carry out the hyperthermia. The results of experiments show that the techniques in this study can actually form large heating regions under the skull phantom, demonstrating its practicality for clinical use.
Conclusion: The transducer with smaller PZT element’s surface area and larger number of PZT elements can not only form accurate focal zone but create large enough and effective heating regions with phase correction and multi-foci techniques. The results show its feasibility and practicality for clinical brain metastasis tumor hyperthermia.
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Chen, Guan-Ming, and 陳冠銘. "Development and Investigation of High Frequency MR-guided Ring-Shaped Phased-Array Ultrasound Transducer for Breast Tumor Thermal Therapy." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/62135692301362801240.
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碩士<br>國立臺灣大學<br>醫學工程學研究所<br>101<br>High Intensity Focused Ultrasound (HIFU) can achieve a non-invasive treatment using sound wave transmission to heat the desired region. In this study, we tried to develop a ring-shaped HIFU transducer for breast tumors to generate thermal lesions in the tip region of the breast and to execute thermal therapy in the bottom of the breast.
Using piezocomposite material for ultrasonic transducer can lower the acoustic impedance as well as increase the electro-mechanical coupling factor. The size of transducer is 100 mm in radius, 100 mm in radius of curvature, 25 mm in height and 2.5 MHz in working frequency. The transducer consists of 16 elements. To verify the output efficiency and stability, we measured the piezoelectric parameter d33, acoustic impedance and electro-acoustic efficiency.
At the present, the high frequency ring-shaped ultrasound transducer cannot reach the requirements for a HIFU, while it can heat fresh pork tissues. This ultrasound transducer can transmit the acoustic power to the center of a 6 cm gelatin phantom to effectively raise the temperature.
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Huang, Yu-Shun, and 黃裕順. "Investigation of Dual Phased-Array Ultrasound Transducers for Breast Tumor Thermal Surgery." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/68998888549875357579.
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碩士<br>臺灣大學<br>醫學工程學研究所<br>95<br>The purpose of this study was to investigate the feasibility of using two curved ultrasound phased arrays with a rapid focus-scanning scheme for breast tumor thermal therapy. The driving frequency, radius of curvature, length and width of the phased arrays are 1.0 MHz, 15 cm, 16 cm and 1.5 cm, respectively. The two curved arrays were arranged face-to-face with a distance of 24 cm, and the breast was set between the two arrays to have the planning target volume (PTV) located at the center. The foci of the phased arrays were located at the PTV and scan sequentially. After an appropriate sonication time, the set of arrays was rotated 90 degree and then continued the sonication to achieve a uniform heating for the PTV without overheating the normal tissues. The location of PTV, blood perfusion rate, the ratio of sonication time before and after the rotation, and a superficial PTV has been studied. The computer simulation and experiments with color-changeable phantom and flesh pork phantom had been used to evaluate the proposed heating system. The results indicated that the heating system was able to create a uniform heating in the PTV with a minimum acoustic power deposition in ribs due to the acoustic beam parallel to the ribs. In addition, the temperature rise on the breast surface could be minimized since a sufficient acoustic window was used for the proposed heating system. A shallow PTV could even be heated as a low temperature of cooling water was used. The results of this study showed that the two ultrasound phased-arrays with a suitable arrangement and heating scheme was able to achieve a uniform heating for breast tumor thermal therapy without overheating the ribs and the skin within a short treatment time.
Books on the topic "Phased-array ultrasound transducer"
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Yeh, Shochi. Theoretical and experimental evaluation of radiation patterns generated by phased array ultrasound transducers with mechanical and electronic focussing. [s.n.], 1986.
Find full textBook chapters on the topic "Phased-array ultrasound transducer"
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Chen, Jianyu, Shun Suzuki, Tao Morisaki, et al. "Sound Pressure Field Reconstruction for Ultrasound Phased Array by Linear Synthesis Scheme Optimization." In Haptics: Science, Technology, Applications. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-06249-0_17.
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AbstractUltrasound phased array is a device that is usually used to provide mid air tactile sensations like three-dimensional shape haptics images by generating various specific sound fields. Forming foci for the ultrasound phased array using the linear synthesis scheme (LSS) is a straightforward technique to induce tactile feeling. The matching phase set for each focal point is calculated separately in LSS, and then they are linearly superimposed to generate multiple focal points. Due to the fact that adding an arbitrary offset to the entire phase pattern has no effect on the generated focus patterns, adjusting the offset in linear summation may result in a superior sound field. In our study, we propose that optimize the offset before linear superposition. These offsets are determined based on the number of focal points, which means it will not cause an explosive increase in computing cost with the increase of transducers. To optimize the offset of each focus pressure generated by LSS, we used a greedy algorithm with a brute-force search optimization method. The computing cost of our proposed method is dictated by the number of foci after calculating the phase sets of LSS once. We demonstrate the proposed method’s optimum performance in varied numbers of foci and transducers in this study.
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Binder, Thomas. "Technical equipment for echocardiography." In ESC CardioMed, edited by Frank Flachskampf. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0084.
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Advances in ultrasound technology are shaping the way we apply echocardiography today. The industry has now developed a vast array of scanners that are targeted to different clinical requirements, budgets, and applications. In general, they can be categorized into high-end, mid-range, portable, and handheld scanners. Aside from image quality, much emphasis is placed on ergonomics, the user interface, and the patient data archiving system, which are all important to optimize workflow. Phased array transducers are used in echocardiography. Much of the signal processing (i.e. beam forming) occurs within the transducer. Further developments in computer processing and transducer technology have also led to the development of three-dimensional (3D) matrix array probes. Other transducer types necessary for a fully functional echocardiography laboratory include the pencil probe (for continuous wave spectral Doppler recordings) and the transoesophageal probe, which now also permits live 3D transoesophageal echocardiography scanning. Many of the functionalities of modern scanners are ‘software based’, where packages for specific applications such as stress echocardiography, speckle tracking, or advanced 3D image analysis can be integrated into the systems.
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Benkeser, P. J., E. F. Goff, and W. O. Rice. "ANALYSIS OF A PULSE-ECHO ULTRASOUND TAPERED PHASED ARRAY TRANSDUCER." In Ultrasonics International 87. Elsevier, 1987. http://dx.doi.org/10.1016/b978-0-408-02348-1.50145-1.
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Friedman, Paul A., and Samuel J. Asirvatham. "Use of Intracardiac Echocardiography in Cardiac Electrophysiology." In Mayo Clinic Electrophysiology Manual. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199941193.003.0002.
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Intracardiac echocardiography is increasingly used during invasive electrophysiology procedures. Common applications include guiding transseptal puncture, assessing potential complications, and identifying structures invisible under fluoroscopy. It is important to distinguish intravascular ultrasound from intracardiac ultrasound. Intravascular ultrasound uses high-frequency transducers that provide excellent high-resolution images but have limited tissue penetration. Intracardiac imaging uses lower frequencies, increasing tissue penetration to 14 cm and permitting “whole heart” imaging. The purpose of this brief introduction is to provide practical points of reference for use of intracardiac echocardiography and orientation to the images that follow in the remainder of the book. Thus, only images from the phased-array system are included.
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Campbell, Stuart. "A history of ultrasound in obstetrics and gynaecology." In Ultrasound in Clinical Diagnosis. Oxford University Press, 2011. http://dx.doi.org/10.1093/oso/9780199602070.003.0012.
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It is often difficult to know when most developments in medicine actually begin. They tend to evolve and many people will claim the credit of being the first to make the breakthrough. with ultrasound in obstetrics and gynaecology there is no such doubt for it had a very definite beginning with the 1958 classic Lancet paper by Ian Donald, John McVicar, and Tom Brown ‘The investigation of abdominal masses by pulsed ultrasound’. Actually this is an unfortunate title because it does not identify what was truly unique about the paper which is that it was entirely devoted to ultrasound studies in clinical obstetrics and gynaecology and contained the first ultrasound images of the fetus and also gynaecological masses. The other unique feature was that these were the first images taken with a compound contact scanner which was the first practical scanning machine. It would be short-sighted to write about the development of medical ultrasound without mentioning some of the great scientists of the 19th and 20th centuries whose conceptual advances paved the way for the modern ultrasound machine. Thomas Young in 1801 described ‘phase shifting’ in relation to light waves but this concept is used in ultrasound phased array systems to control interference patterns and is used in the production of three-dimensional (3-D) images. Christian Doppler in 1842 described what we now call the ‘Doppler effect’ in relation to the motion of stars but this principle is now used as the basis for blood flow studies in pelvic vessels and the fetus. Pierre Curie in 1880 described the piezo electric effect whereby mechanical distortion of ceramic crystals would produce an electric charge; the reverse of this effect is used in all transducers to generate ultrasonic waves. Paul Langevin in 1915 built the first hydrophone which used ultrasonic waves to locate the position and distance of submarines and is the principle behind the measurement of the fetus and abdominal masses by ultrasound. The development of Radar by watson-watt and his team using electromagnetic waves in 1943 was later adapted for ultrasound to produce two-dimensional (2-D) images.
Conference papers on the topic "Phased-array ultrasound transducer"
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Rivens, Ian. "A Phased Strip Array HIFU Transducer." In THERAPEUTIC ULTRASOUND: 5th International Symposium on Therapeutic Ultrasound. AIP, 2006. http://dx.doi.org/10.1063/1.2205510.
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Johansen, Tonni Franke, Philip Erik Buschmann, Knut Marius Røsberg, Anja Diez, and Erlend Magnus Viggen. "Ultrasonic Well Integrity Logging Using Phased Array Technology." In ASME 2023 42nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2023. http://dx.doi.org/10.1115/omae2023-108101.
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Abstract Ultrasonic well integrity logging is an important and common procedure for well completion and plug-and-abandonment operations. Typical logging tools employ single-element ultrasound transducers. In medical ultrasound imaging, however, more flexible phased arrays are the standard. This paper presents a first set of experimental results obtained with up to two linear 32-element phased arrays that are specifically designed for plug-and-abandonment operations in terms of their centre frequency. The experiments encompass pulse-echo and pitch-catch studies for different incidence angles and aperture sizes on plates and pipes with wall thickness as encountered in the offshore industry. The pulse-echo experiment is backed up by simulations, and shows that effect of the incidence angle on the pipe resonance’s frequency and strength is weak and more strong, respectively, and that the effect depends on the frequency response and directivity of the transducer. The pitch-catch experiment demonstrates the importance of carefully choosing the right angle of incidence to excite the intended wave modes.
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Taheri, Hossein, Fereidoon Delfanian, and Jikai Du. "Acoustic Emission and Ultrasound Phased Array Technique for Composite Material Evaluation." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62447.
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The successful application of various acoustic evaluation techniques to composite materials and structures depends on the understanding of the acoustic wave propagation mechanisms. However, due to the anisotropic nature of composite materials, where the acoustic signal velocity and attenuation depend on its traveling direction, the correlation of the different material failure modes to the recorded acoustic signals, such as during of an acoustic emission (AE) inspection, is difficult to be defined. This issue becomes even more challenging for ultrasound phased array technique, where unlike a conventional ultrasound single element transducer, an ultrasound phased array of sensors will generate and receive acoustic energy at various desired directions and locations. Such heightened flexibility and sensitivity is essential for the complex shape of modern composite structures. In this paper, the influence of fiber orientation on AE signal was first studied. AE parameters such as counts, duration, energy, rise time and amplitude for aluminum and composite plate were analyzed in MS-Excel and results were compared to AE software. Acoustic velocities along various fiber directions were also theoretically studied and experimentally measured. Then ultrasound phased array technique and related parameters such as ultrasound beam angle and focusing, frequency and material attenuation factors were quantitatively analyzed, and the optimization and limitation of ultrasound phased array inspection procedure were summarized.
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Song, Junho, Kullervo Hynynen, and Emad S. Ebbini. "A 1372-element Large Scale Hemispherical Ultrasound Phased Array Transducer for Noninvasive Transcranial Therapy." In 8TH INTERNATIONAL SYMPOSIUM ON THERAPEUTIC ULTRASOUND. AIP, 2009. http://dx.doi.org/10.1063/1.3131452.
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Du, Jikai, and Ali Rajhi. "Ultrasound Phased Array for High Acoustic Attenuation Thick Composite Materials." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52298.
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Composite materials and structures are increasingly being applied in aerospace, marine, and wind power industries, as well as in commercial products. One main reason for the scientific interest in composite materials is their tailorable mechanical properties. However, because of the fiber-direction-dependent nature of its physical and mechanical properties, composite material’s property and failure behaviors are usually complex, typically involving various mechanisms depending on applications. Nondestructive testing plays a key role during composite fabrication and maintenance in service. Among the variety of nondestructive techniques available, ultrasound phased array technique has emerged as a promising new approach. Unlike a conventional ultrasound single element transducer, an ultrasound phased array sensor can control and focus acoustic energy to the desired directions and locations. This heightened flexibility and sensitivity is essential given complex shape of modern composite structures. Despite such promise, understanding and application of ultrasound phased array technique is limited due to the anisotropic nature of composite materials, as well as its high acoustic attenuation. Attenuation and velocity dispersion are the two major challenges to the ultrasound evaluation of composite structures; these two factors complicate the control of phased array ultrasound propagation both theoretically and experimentally. This is especially true for thick high attenuation carbon fiber or glass fiber composite materials that have been widely applied in aerospace and wind turbine industries. In our study, ultrasound phased array technique was applied to increase the acoustic penetration power in high acoustic attenuation composite materials. First, ultrasound phased array signal in isotropic materials was studied to calibrate the probe parameters. Then for composite materials, the dependence of ultrasound field on the number of active elements, steering angles, beam focusing laws and on the characteristics of materials was analyzed and optimized through theoretical simulations and experimental evaluations. Results showed that the steering angles and the parameters of beam focusing laws might change the ultrasound beam intensity and uniformity, which had a significant influence on the sensitivity and resolution of the technique; the anisotropic properties of composite materials could distort the ultrasound beam, which made the calibration a necessary and important procedure during practical inspections. The influence of ultrasound frequency and beam angle were also quantitatively evaluated. The proposed research has the potential to apply ultrasound phased array technique to the detection of defects in composite materials and the evaluation of composite structural health. The study of the interaction between ultrasound and composite structures will open the window for the successful application of ultrasound phased array technique.
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Boerkamp, Christiaan, Tiago L. Costa, and Jovana Jovanova. "Design of a Flexible Transducer Array and Characterisation of Piezoelectric Sensors for Curvature Compensation." In ASME 2022 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/smasis2022-90707.
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Abstract Flexible ultrasound has emerged as the basis for wearable devices in healthcare. In this work, a flexible 1D phased transducer array has been proposed. This transducer array includes piezoelectric sensors underneath the transducer array, which detect its local curvature at different locations, corresponding to the positions of each piezoelectric sensor. Using FEA a simulation study was created, resulting in a deformed transducer array in which the number of curves and the number of sensors are varied. The piezoelectric sensors detect the local curvature resulting in a displacement map along the array. The sensing error of these sensors is calculated by taking the difference between the detected curvature from the sensors and the actual curvature the PCB was subjected to during the simulations. The results of these simulations show that, an increase of sensors results in a noticeable decrease in sensing error up to 9 sensors. Increasing the number of sensors after that point decreases the sensing error to a negligible value. The curvature information gathered from the piezoelectric sensors was then used to allow for the generation of focused ultrasound beams. To enable this, ultrasound beamforming algorithms were augmented to include curvature correction. These simulations showed that, despite a slight decrease in beam pressure of a curved transducer array compared to an uncurved array, the sensors can effectively detect and compensate for curvature in ultrasound transducer arrays.
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Tsakalakis, Michail, and Nikolaos G. Bourbakis. "Designing of a low-cost, volumetric multi — Transducer phased array ultrasound system." In 2015 IEEE 15th International Conference on Bioinformatics and Bioengineering (BIBE). IEEE, 2015. http://dx.doi.org/10.1109/bibe.2015.7367624.
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Margolis, Ryan, Lokesh Basavarajappa, Junjie Li, and Kenneth Hoyt. "Ultrasound Image-Guided Drug Delivery using a Spherically Focused Phased Array Transducer." In 2021 IEEE International Ultrasonics Symposium (IUS). IEEE, 2021. http://dx.doi.org/10.1109/ius52206.2021.9593806.
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Sun, Wujun, Ping Zhang, Xiaojing Zhang, et al. "Simulation of Temperature Field Induced by 8-Element Phased Array HIFU Transducer with Concave Spherical Surface." In 10TH INTERNATIONAL SYMPOSIUM ON THERAPEUTIC ULTRASOUND (ISTU 2010). AIP, 2011. http://dx.doi.org/10.1063/1.3607949.
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Konetzke, Eric, Matthias Rutsch, Maik Hoffmann, et al. "Phased array transducer for emitting 40-kHz air-coupled ultrasound without grating lobes." In 2015 IEEE International Ultrasonics Symposium (IUS). IEEE, 2015. http://dx.doi.org/10.1109/ultsym.2015.0019.
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