The Experts below are selected from a list of 12930 Experts worldwide ranked by ideXlab platform
Laura Curiel - One of the best experts on this subject based on the ideXlab platform.
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An integrated full-bridge Class-DE Ultrasound Transducer driver for HIFU applications
2016 14th IEEE International New Circuits and Systems Conference (NEWCAS), 2016Co-Authors: Ruiqi Song, Carlos Christoffersen, Samuel Pichardo, Laura CurielAbstract:This paper presents an integrated MRI-compatible full-bridge Class-DE Ultrasound Transducer driver design for HIFU applications. This design includes a digital logic unit to individually control the phase and duty ratio of each Transducer when the driver is used in an array configuration. This work also shows the performance of the proposed driver with three different ultrasonic Transducers. Simulation results predict at least 89% efficiency for the two Transducers that support ideal Class-DE operation without matching networks. The proposed driver has been implemented by using AMS AG H35 CMOS process. The total die area of the driver is 3 mm2.
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Class-DE Ultrasound Transducer Driver for HIFU Therapy
IEEE Transactions on Biomedical Circuits and Systems, 2016Co-Authors: Carlos Christoffersen, Wai Wong, Samuel Pichardo, Greg Togtema, Laura CurielAbstract:This paper presents a practical implementation of an integrated MRI-compatible CMOS amplifier capable of directly driving a piezoelectric Ultrasound Transducer suitable for high-intensity focused Ultrasound (HIFU) therapy. The amplifier operates in Class DE mode without the need for an output matching network. The integrated amplifier has been implemented with the AMS AG H35 CMOS process. A class DE amplifier design methodology for driving unmatched piezoelectric loads is presented along with simulation and experimental results. The proposed design achieves approximately 90% efficiency with over 800 mW of output power at 1010 kHz. The total die area including pads is 2 mm2. Compatibility with MRI was validated with B1 imaging of a phantom and the amplifier circuit.
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An integrated Ultrasound Transducer driver for HIFU applications
2013 26th IEEE Canadian Conference on Electrical and Computer Engineering (CCECE), 2013Co-Authors: Wai Wong, Carlos Christoffersen, Samuel Pichardo, Laura CurielAbstract:This paper presents for the first time an MRI-compatible integrated CMOS amplifier capable of directly driving a piezoelectric Ultrasound Transducer for High Intensity Focused Ultrasound (HIFU) applications. The amplifier operates in class DE mode loaded with a piezoelectric Ultrasound Transducer connected in parallel with a shunt capacitor. There is no need for external inductors. The integrated amplifier is implemented with the Teledyne-DALSA 0.8 μm CMOS process. Modeling of the piezoelectric Transducer and amplifier design considerations are presented, followed by simulation results obtained using the Spectre simulator. The proposed design achieves over 80% efficiency with 1 W of output power at 1 MHz and an acceptable third harmonic level. The estimated die area of the amplifier is 2 mm2.
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CCECE - An integrated Ultrasound Transducer driver for HIFU applications
2013 26th IEEE Canadian Conference on Electrical and Computer Engineering (CCECE), 2013Co-Authors: Wai Wong, Carlos Christoffersen, Samuel Pichardo, Laura CurielAbstract:This paper presents for the first time an MRI-compatible integrated CMOS amplifier capable of directly driving a piezoelectric Ultrasound Transducer for High Intensity Focused Ultrasound (HIFU) applications. The amplifier operates in class DE mode loaded with a piezoelectric Ultrasound Transducer connected in parallel with a shunt capacitor. There is no need for external inductors. The integrated amplifier is implemented with the Teledyne-DALSA 0.8 μm CMOS process. Modeling of the piezoelectric Transducer and amplifier design considerations are presented, followed by simulation results obtained using the Spectre simulator. The proposed design achieves over 80% efficiency with 1 W of output power at 1 MHz and an acceptable third harmonic level. The estimated die area of the amplifier is 2 mm2.
Liangzhong Xiang - One of the best experts on this subject based on the ideXlab platform.
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x ray induced acoustic computed tomography with an Ultrasound Transducer ring array
Applied Physics Letters, 2017Co-Authors: Shanshan Tang, D H Nguyen, Ali Zarafshani, Chris Ramseyer, B Zheng, Liangzhong XiangAbstract:The objective of this study is to develop and test a unique X-ray-induced acoustic computed tomography system that combines the advantages of high X-ray imaging contrast and high ultrasonic spatial resolution. The system features a 5 MHz 128-element Ultrasound Transducer ring-array formed into a full circular aperture. A parallel data receiver, which consists of a dedicated 128-channel preamplifier and a 128-channel data acquisition module, provides full tomographic imaging at a speed of up to 25 frames per second. Details of the system design and calibration are presented, along with the characteristic results of the imaging resolution. The tomographic imaging performance is demonstrated through images of a phantom with a spatial resolution up to 138 μm. The study results indicate that this imaging device and the methodology provide a rapid and high resolution approach for the dynamic imaging of information, and it may have the potential for becoming a promising noninvasive imaging modality to be used in...
Helen Lai Wa Chan - One of the best experts on this subject based on the ideXlab platform.
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development of a 20 mhz wide bandwidth pmn pt single crystal phased array Ultrasound Transducer
Ultrasonics, 2017Co-Authors: Chiman Wong, Yan Chen, Helen Lai Wa ChanAbstract:Abstract In this study, a 20-MHz 64-element phased-array Ultrasound Transducer with a one-wavelength pitch is developed using a PMN-30%PT single crystal and double-matching layer scheme. High piezoelectric (d33 > 1000 pC/N) and electromechanical coupling (k33 > 0.8) properties of the single crystal with an optimized fabrication process involving the photolithography technique have been demonstrated to be suitable for wide-bandwidth (⩾70%) and high-sensitivity (insertion loss ⩽30 dB) phased-array Transducer application. A −6 dB bandwidth of 91% and an insertion loss of 29 dB for the 20-MHz 64-element phased-array Transducer were achieved. This result shows that the bandwidth is improved comparing with the investigated high-frequency (⩾20 MHz) Ultrasound Transducers using piezoelectric ceramic and single crystal materials. It shows that this phased-array Transducer has potential to improve the resolution of biomedical imaging, theoretically. Based on the hypothesis of resolution improvement, this phased-array Transducer is capable for small animal (i.e. mouse and zebrafish) studies.
Senlin Jiang - One of the best experts on this subject based on the ideXlab platform.
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Numerical Study and Optimisation of a Novel Single-Element Dual-Frequency Ultrasound Transducer.
Sensors, 2018Co-Authors: Senlin JiangAbstract:A dual-frequency Ultrasound Transducer (DFUT) is usually preferred for its numerous advantageous applications, especially in biomedical imaging and sensing. However, most of DFUTs are based on the combination of fundamental and harmonic operations, or integration of multiple different single-frequency Ultrasound Transducers, hindering perfect beam alignment and acoustic impedance matching. A novel single-element DFUT has been proposed in this paper. A small piezoelectric membrane is used as the high-frequency Ultrasound Transducer, which is stacked on a large non-piezoelectric elastic membrane with a groove used as the low-frequency capacitive Ultrasound Transducer. Such a capacitive-piezoelectric hybrid structure is theoretically analysed in details, based on the electrostatic attraction force and converse piezoelectric effect. Both the low and high resonance frequencies are independently derived, with a maximum deviation of less than 4% from the finite element simulations. Besides, a lumped-parameter equivalent circuit model of combining both the capacitive and piezoelectric Ultrasound Transducers was also described. Based on our dual-frequency structure design, a high-to-low frequency ratio of about 2 to more than 20 could be achieved, with easy and independent controllability of two frequencies, and the high-frequency operation shows at least an order-of-magnitude displacement sensitivity improvement compared with the conventional harmonic operations.
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A novel single-element dual-frequency Ultrasound Transducer for image-guided precision medicine
2017 IEEE International Ultrasonics Symposium (IUS), 2017Co-Authors: Senlin JiangAbstract:High-resolution Ultrasound imaging of tissues provides a higher possibility for the early diagnosis of various diseases and plays an important role in high-precision targeted treatment. However, it unavoidably suffers from low penetration depth and short depth of field (DOF) due to its high operating frequency. A novel single-element dual-frequency Ultrasound Transducer (DFUT) has been designed and studied, which consists of three conductive metal layers, a large capacitive elastic layer used as the low-frequency capacitive micromachined ultrasonic Transducer (CMUT), and a small piezoelectric layer used as the high-frequency piezoelectric micromachined ultrasonic Transducer (PMUT). This capacitive-piezoelectric hybrid structure is able to operate at both CMUT and PMUT modes at two different frequencies. Both theoretical analysis and finite element method (FEM) simulations have been carried out towards the frequency performance and optimizing the dimensions of the DFUT. The results show that the novel structure could be in operation at both low frequency of 5.9MHz and high frequency of 26.6MHz, which can be adopted as imaging and/or therapy operations. With the combination of CMUT and PMUT modes, the single-element DFUT provides the advantages of high-resolution (3cm for CMUT operation), which may significantly inspire the imaging-guided precision medicine applications.
Robert Puers - One of the best experts on this subject based on the ideXlab platform.
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resonating shell a spherical omnidirectional Ultrasound Transducer for underwater sensor networks
Sensors, 2019Co-Authors: Sina Sadeghpour, Michael Kraft, Sebastian Meyers, Jeanpierre Kruth, Jozef Vleugels, Robert PuersAbstract:This paper presents the design and fabrication process of a spherical-omnidirectional Ultrasound Transducer for underwater sensor network applications. The Transducer is based on the vibration of two hemispheres with a thickness of 1 mm and an outer diameter of 10 mm, which are actuated by two piezoelectric ring elements. Since the Ultrasound wave is generated by the vibration of the two hemispheres, a matching layer is not required. Silicon Carbide (SiC) is used as the material of the hemispherical shells of the Transducer. The shells were fabricated by laser sintering as an additive manufacturing method, in which the hemispheres were built layer by layer from a powder bed. All manufactured Transducers with an outer dimension of 10 × 14.2 mm and a center frequency of 155 kHz were measured in a water tank by a hydrophone or in mutual communication. The circumferential source level was measured to vary less than 5dB. The power consumption and the insertion loss of the Transducer, ranging from 100 μ W to 2.4 mW and 21.2 dB, respectively, along with all other measurements, prove that the Transducer can transmit and receive Ultrasound waves omnidirectionally at tens of centimeters intervals with a decent power consumption and low actuation voltage.
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Coupled Piezoelectric Bulk-Micromachined Ultrasound Trasndcuer (cPB-MUT): An Ultrasound Transducer with Enhanced Pressure Response in Liquid and Dense Medium
2019 IEEE International Ultrasonics Symposium (IUS), 2019Co-Authors: Sina Sadeghpour, Michael Kraft, Robert PuersAbstract:A new type of Ultrasound Transducer based on piezoelectric micromachined Ultrasound Transducer (pMUT) technology was developed, which is called coupled piezoelectric bulk-micromachined Ultrasound Transducer (cPB-MUT). In this Transducer technology the vibration of small pMUTs are coupled to the bulk silicon substrate through the vibration of water or any other dense medium; this produces a strong vibration in the entire substrate. CPB-MUT was designed for underwater applications such as underwater sensor networks and underwater communication in the range of 1-2 meters. A cPB-MUT with a resonance frequency of 33 kHz was fabricated. It is capable of producing about 210 Pa/V at 1cm underwater.
