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https://www.readbyqxmd.com/read/28231486/coded-excitation-waveform-engineering-for-high-frame-rate-synthetic-aperture-ultrasound-imaging
#1
Bahman Lashkari, Kaicheng Zhang, Edem Dovlo, Andreas Mandelis
Coded excitation was initially introduced to ultrasound imaging as a method for enhancing the signal-to-noise ratio (SNR). However, this method was also shown to be helpful in conjunction with synthetic aperture transmission for high frame rate imaging. Recently, we introduced two families of mismatched coded excitations based on frequency modulation chirp and combined frequency modulation and Golay code. Here "mismatched" indicates that the coded excitations generate very small cross-correlations among themselves while each has a very strong autocorrelation...
February 12, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28227331/assessing-the-development-of-fetal-myocardial-function-by-a-novel-doppler-myocardial-performance-index
#2
Ahsan H Khandoker, F Marzbanrad, Y Kimura, Saeed Al Nuaimi, M Palaniswami, Ahsan H Khandoker, F Marzbanrad, Y Kimura, Saeed Al Nuaimi, M Palaniswami, Ahsan H Khandoker, Y Kimura, Saeed Al Nuaimi, F Marzbanrad, M Palaniswami
Doppler-derived myocardial performance index are used to assess aspects of systolic and diastolic function in adult as well as fetal heart. The Tei Index (TI) is a useful and non-invasive tool. The aim of this study was to determine normal values of fetal left ventricular (LV) TI in early (16-32 weeks) and late trimester (35-41 weeks) fetuses and to develop a new myocardial performance index (K-index; KI) which focuses on fetal diastolic interval when oxygenated blood from the placenta filled in the LV. Simultaneous recordings of Doppler Ultrasound Signal (DUS) of the LV outflow tracts and fetal electrocardiogram signals were obtained in 55 early- and late-trimester fetuses...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226690/polarity-detection-in-ultrasound-current-source-density-imaging
#3
Zhaohui Wang, Wei-Da Hao, Chung S Leung, Sung-Won Park, Zhaohui Wang, Wei-Da Hao, Chung S Leung, Sung-Won Park, Chung S Leung, Zhaohui Wang, Sung-Won Park, Wei-Da Hao
Modulating the electric dipole field with ultrasound pulse, ultrasound current source density imaging (UCSDI) can detect current direction and form spatial 3D imaging of dipole changing in one period of treatment. As ultrasound pulse passes through the conductive media, it convolves/correlates with the inner product of the electric field of a dipole and lead field of a pair of detectors, making the shifting frequency of polarity lower than the center frequency of the ultrasound pulse. After acoustoelectric (AE) signal is shifted to base band, the AE voltage is positive at anode and negative at cathode...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28224305/high-frequency-color-doppler-ultrasound-as-the-first-diagnostic-and-monitoring-choice-for-early-superficial-high-flow-vascular-malformations
#4
Lei Chang, Dongze Lv, Yunbo Jin, Wenxin Yu, Xi Yang, Gang Ma, Hui Chen, Xiaoxi Lin
Diagnosis and monitoring of early high-flow vascular malformations could be a meaningful pursuit. However, there has been no ideal method for their long-term monitoring and prognosis. We examined 21 early high-flow vascular malformations in this study and deemed that high-frequency color Doppler ultrasound could be regarded as the first diagnostic and monitoring choice for early high-flow vascular malformations at present.
February 21, 2017: Journal of Medical Ultrasonics
https://www.readbyqxmd.com/read/28223839/ultrasound-guided-alcohol-neurolysis-and-radiofrequency-ablation-of-painful-stump-neuroma-effective-treatments-for-post-amputation-pain
#5
Xin Zhang, Yongming Xu, Jin Zhou, Shaofeng Pu, Yingying Lv, Yueping Chen, Dongping Du
BACKGROUND: Post-amputation pain (PAP) is highly prevalent after limb amputation, and stump neuromas play a key role in the generation of the pain. Presently, PAP refractory to medical management is frequently treated with minimally invasive procedures guided by ultrasound, such as alcohol neurolysis and radiofrequency ablation (RFA). OBJECTIVE: To record the immediate and long-term efficacy of alcohol neurolysis and RFA. We first used alcohol neurolysis and then, when necessary, we performed RFA on PAP patients...
2017: Journal of Pain Research
https://www.readbyqxmd.com/read/28219142/-application-of-high-frequency-ultrasound-in-dermabrasion-of-patients-with-deep-partial-thickness-burns
#6
C Y Zang, Y Q Cao, W J Xue, R Zhao, M Zhang, Y H Zhang, Z Feng, Y B Wang
Objective: To investigate the application of high-frequency ultrasound in dermabrasion of patients with deep partial-thickness burns. Methods: Twenty-six patients with deep partial-thickness burns conforming to the study criteria were hospitalized in our unit from March 2015 to March 2016. Patients were all performed with dermabrasion. The structure of skin tissue and blood flow signals of uninjured side and wounds before dermabrasion, and those of wounds immediately post dermabrasion and on post dermabrasion day (PDD) 1, 3, 5, 7, 10, 14, and 21 were detected with high-frequency ultrasound, and the percentage of blood flow signals was calculated...
February 20, 2017: Zhonghua Shao Shang za Zhi, Zhonghua Shaoshang Zazhi, Chinese Journal of Burns
https://www.readbyqxmd.com/read/28217989/comparison-of-endovenous-radiofrequency-ablation-laser-ablation-foam-sclerotherapy-and-surgical-stripping-for-great-saphenous-varicose-veins-extended-5-year-follow-up-of-a-rct
#7
Martin Lawaetz, Julie Serup, Birgit Lawaetz, Lars Bjoern, Allan Blemings, Bo Eklof, Lars Rasmussen
BACKGROUND: This study compares the outcome 5 years after treatment of varicose veins with endovenous radiofrequency ablation (RFA), endovenous laser ablation (EVLA), ultrasound guided foam sclerotherapy (UGFS) or high ligation and stripping (HL/S) by assessing technical efficacy, clinical recurrence and the rate of reoperations. METHODS: Five hundred patients (580 legs) with Great Saphenous Vein (GSV) reflux and varicose veins were randomized to one of the 4 treatments...
February 17, 2017: International Angiology: a Journal of the International Union of Angiology
https://www.readbyqxmd.com/read/28214343/high-resolution-ultrasound-visualization-of-the-deep-branch-of-the-ulnar-nerve
#8
Georg Riegler, Doris Lieba-Samal, Peter C Brugger, Christopher Pivec, Hannes Platzgummer, Martin Vierhapper, Gabriela Muschitz, Suren Jengojan, Gerd Bodner
INTRODUCTION: The value of imaging the deep branch of the ulnar nerve (DBUN) over its entire course has not been clarified. Therefore, this study aimed to evaluate the feasibility of visualizing the DBUN from its origin to the most distal point. METHODS: We performed high-resolution ultrasound (HRUS) with high-frequency probes (18-22MhZ), HRUS-guided ink-marking, and consecutive dissection in 8 fresh cadaver hands. In both hands of 10 healthy volunteers (n=20), the cross-sectional area (CSA) was measured at 2 different locations (R1+R2)...
February 18, 2017: Muscle & Nerve
https://www.readbyqxmd.com/read/28214293/ultra-high-frequency-ultrasound-of-fascicles-in-the-median-nerve-at-the-wrist
#9
Michael S Cartwright, Vanessa Baute, James B Caress, Francis O Walker
INTRODUCTION: An ultra high-frequency (70 MHz) ultrasound device has recently been approved for human use. This study was conducted to determine if this device facilitates counting of fascicles within the median nerve at the wrist. METHODS: Twenty healthy volunteers underwent imaging of the median nerve at the wrist bilaterally. The number of fascicles in each nerve was counted by two independent raters. RESULTS: The mean fascicle number was 22...
February 18, 2017: Muscle & Nerve
https://www.readbyqxmd.com/read/28212081/a-comparative-analysis-of-cmut-receiving-architectures-for-design-optimization-of-integrated-transceiver-front-ends
#10
Marco Sautto, Alessandro Stuart Savoia, Fabio Quaglia, Giosue Caliano, Andrea Mazzanti
A formal comparison between fundamental RX amplifier configurations for Capacitive Micromachined Ultrasonic Transducers (CMUT) is proposed in this paper. The impact on both RX and the pulse-echo frequency response and on the output SNR are thoroughly analysed and discussed. It is shown that the resistive-feedback amplifier yields a band-pass RX frequency response, while both open-loop voltage and capacitivefeedback amplifiers exhibit a low-pass frequency response. For a given power dissipation, it is formally proved that a capacitivefeedback amplifier provides a remarkable SNR improvement against the commonly adopted resistive feedback stage, achieved at the expense of a reduced pulse-echo center frequency, making its use convenient in low and mid-frequency ultrasound imaging applications...
February 13, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28211510/broadband-gradient-impedance-matching-using-an-acoustic-metamaterial-for-ultrasonic-transducers
#11
Zheng Li, Dan-Qing Yang, Shi-Lei Liu, Si-Yuan Yu, Ming-Hui Lu, Jie Zhu, Shan-Tao Zhang, Ming-Wei Zhu, Xia-Sheng Guo, Hao-Dong Wu, Xin-Long Wang, Yan-Feng Chen
High-quality broadband ultrasound transducers yield superior imaging performance in biomedical ultrasonography. However, proper design to perfectly bridge the energy between the active piezoelectric material and the target medium over the operating spectrum is still lacking. Here, we demonstrate a new anisotropic cone-structured acoustic metamaterial matching layer that acts as an inhomogeneous material with gradient acoustic impedance along the ultrasound propagation direction. When sandwiched between the piezoelectric material unit and the target medium, the acoustic metamaterial matching layer provides a broadband window to support extraordinary transmission of ultrasound over a wide frequency range...
February 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28211204/evaluation-of-the-enhanced-permeability-and-retention-effect-in-the-early-stages-of-lymph-node-metastasis
#12
Mamoru Mikada, Ariunbuyan Sukhbaatar, Yoshinobu Miura, Sachiko Horie, Maya Sakamoto, Shiro Mori, Tetsuya Kodama
Most solid cancers spread to new sites via the lymphatics before hematogenous dissemination. However, only a small fraction of an intravenously administered anti-cancer drug enters the lymphatic system to reach metastatic lymph nodes (LNs). Here, we show that the enhanced permeability and retention (EPR) effect is not induced during the early stages of LN metastasis. Luciferase-expressing tumor cells were injected into the subiliac LN of the MXH10/Mo-lpr/lpr mouse to induce metastasis to the proper axillary LN (PALN)...
February 17, 2017: Cancer Science
https://www.readbyqxmd.com/read/28208584/hybrid-visible-light-and-ultrasound-based-sensor-for-distance-estimation
#13
Jose Rabadan, Victor Guerra, Rafael Rodríguez, Julio Rufo, Martin Luna-Rivera, Rafael Perez-Jimenez
Distance estimation plays an important role in location-based services, which has become very popular in recent years. In this paper, a new short range cricket sensor-based approach is proposed for indoor location applications. This solution uses Time Difference of Arrival (TDoA) between an optical and an ultrasound signal which are transmitted simultaneously, to estimate the distance from the base station to the mobile receiver. The measurement of the TDoA at the mobile receiver endpoint is proportional to the distance...
February 10, 2017: Sensors
https://www.readbyqxmd.com/read/28204998/discrimination-between-emboli-and-artifacts-for-outpatient-transcranial-doppler-ultrasound-data
#14
Blaise Kévin Guépié, Bruno Sciolla, Fabien Millioz, Marilys Almar, Philippe Delachartre
This paper addresses the detection of emboli in transcranial Doppler ultrasound data acquired from an original portable device. The challenge is the removal of several artifacts (motion and voice) intrinsically related to long-duration (up to 1 h 40 mn per patient) outpatient signals monitoring from this device, as well as high intensities due to the stochastic nature of blood flow. This paper proposes an adapted removal procedure. This firstly consists of reducing the background noise and detecting the blood flow in the time-frequency domain using a likelihood method for contour detection...
February 15, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28182095/early-detection-of-tibial-cartilage-degradation-and-cancellous-bone-loss-in-an-ovariectomized-rat-model
#15
Yinong Wang, Zhiwei Liu, Qing Wang, Qianjin Feng, Wufan Chen
This study aimed to investigate degradation of the articular cartilage and loss of the cancellous bone in an ovariectomized (OVX) rat model simulating early human menopausal stage. Fourteen health female Sprague-Dawley rats were randomly divided into two groups (n = 7 per group): an OVX group that underwent bilateral ovariectomy to create an OVX model with low estrogen levels and a sham group in which only the periovarian fatty tissue was exteriorized. All the animals were sacrificed at 3 weeks after ovariectomy...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28170150/double-strand-breaks-in-a-genome-sized-dna-caused-by-ultrasound-high-frequency-pulsing-induces-greater-damage-than-cw-sonication-and-low-frequency-pulsing-causes-less-damage
#16
Takahiro Kenmotsu, Rinko Kubota, Yusuke Yamashita, Yuko Yoshikawa, Kenji Yoshida, Yoshiaki Watanabe, Tadayuki Imanaka, Kenichi Yoshikawa
DNA double-strand breaks (DSBs) caused by ultrasound were evaluated in a quantitative manner through the use of single-molecule observation with fluorescence microscopy. We compared the effect of time-interval, or pulse, sonication to that of continuous wave (CW) sonication at a fixed frequency of 30 kHz. Pulses caused fewer DSBs than CW sonication, under the same total input energy of ultrasound, when the pulse repetition period was above the order of a second(s). In contrast, pulses caused more DSBs than CW sonication for a pulse width shorter than a second(s)...
February 7, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28169126/medium-high-frequency-ultrasound-and-ozone-based-advanced-oxidation-for-amoxicillin-removal-in-water
#17
Rana Kıdak, Şifa Doğan
In this study, treatment of an antibiotic compound amoxicillin by medium-high frequency ultrasonic irradiation and/or ozonation has been studied. Ultrasonic irradiation process was carried out in a batch reactor for aqueous amoxicillin solutions at three different frequencies (575, 861 and 1141kHz). The applied ultrasonic power was 75W and the diffused power was calculated as 14.6W/L. The highest removal was achieved at 575kHz ultrasonic frequency (>99%) with the highest pseudo first order reaction rate constant 0...
January 28, 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28167464/high-frequency-ultrasound-features-and-pathological-characteristics-of-medullary-thyroid-carcinoma
#18
Hua Wang, Mengmeng Liu, Jianqiu Yang, Yimin Song
To study high-frequency ultrasound features and pathological characteristics of medullary thyroid carcinoma (medullary thyroid carcinoma, MTC) with the purpose to improve the diagnostic accuracy of this disease. The clinical data of 20 cases of patients with MTC confirmed by the clinical surgery were retrospectively analyzed. And the high-frequency ultrasound features were analyzed and compared with the pathological characteristics. There were 16 cases with tumor invasion into one side of the thyroid gland; 17 cases with tumor in the middle-upper pole of the thyroid gland...
November 2016: Pakistan Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28167348/3d-functional-ultrasound-imaging-of-the-cerebral-visual-system-in-rodents
#19
Marc Gesnik, Kevin Blaize, Thomas Deffieux, Jean-Luc Gennisson, José-Alain Sahel, Mathias Fink, Serge Picaud, Mickaël Tanter
3D functional imaging of the whole brain activity during visual task is a challenging task in rodents due to the complex tri-dimensional shape of involved brain regions and the fine spatial and temporal resolutions required to reveal the visual tract. By coupling functional ultrasound (fUS) imaging with a translational motorized stage and an episodic visual stimulation device, we managed to accurately map and to recover the activity of the visual cortices, the Superior Colliculus (SC) and the Lateral Geniculate Nuclei (LGN) in 3D...
February 3, 2017: NeuroImage
https://www.readbyqxmd.com/read/28163679/a-phase-locking-analysis-of-neuronal-firing-rhythms-with-transcranial-magneto-acoustical-stimulation-based-on-the-hodgkin-huxley-neuron-model
#20
Yi Yuan, Na Pang, Yudong Chen, Yi Wang, Xiaoli Li
Transcranial magneto-acoustical stimulation (TMAS) uses ultrasonic waves and a static magnetic field to generate electric current in nerve tissues for the purpose of modulating neuronal activities. It has the advantage of high spatial resolution and penetration depth. Neuronal firing rhythms carry and transmit nerve information in neural systems. In this study, we investigated the phase-locking characteristics of neuronal firing rhythms with TMAS based on the Hodgkin-Huxley neuron model. The simulation results indicate that the modulation frequency of ultrasound can affect the phase-locking behaviors...
2017: Frontiers in Computational Neuroscience
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