19 research outputs found

    Measurement of magnetic fields radiated from ESD using field sensors

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    The goal of this paper is to show that commercial sensors, whose frequency response is not specifically designed, can be effectively used to measure very fast transient fields applying a proper reconstructing procedure based on the knowledge of the sensor transfer function. To do this, it is necessary to characterize a structure supporting a transverse electromagnetic (TEM) field, that will be used to set up a calibration procedure for elementary magnetic field sensors. The approach is completely analytical and allows us to knowrigorously the field inside the structure. From the knowledge of this field, the transfer function of the sensor, in amplitude and phase, is evaluated up to 2 GHz. The complete characterization of the sensor allows us to reconstruct the sensed field from its output voltage waveform. The calibration procedure is carried out in time domain and therefore the fast Fourier transform (FFT) algorithm is used to achieve the sensor transfer function, as well as an inverse FFT (IFFT) is necessary to retrieve the transient impinging field. An experimental validation of the procedure shows the consistency of the approach

    Transvaginal ultrasonographic diagnosis of adenomyosis in female patients suffering from uterine fibromatosis

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    Adenomyosis is an underestimated pathology frequently responsible of unknown origin pelvic pain and uterine enlargement. It is hyperestrinic condition with poor specific symptomatology and preoperative diagnostic tools are very few. The most important of them, ultrasound, has improved its diagnostic capacity with the introduction of transvaginal way of examination. However, for the ultrasound resemblance, the common etiopathogenetic origin and the symptomatologic likeness between adenomyosis and uterine leiomyomatosis, a problem still open is the differential diagnosis between these two pathologies especially when both are present in the same subject. In our study where the preoperative ultrasound was followed by surgical finding, we try to give some ultrasonographical guidelines to discern among these two pathologic conditions

    Amniotic fluid nitric oxide and uteroplacental blood flow in pregnancy complicated by intrauterine growth retardation

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    To examine the correlation between placental nitric oxide production and uteroplacental blood flow. Thirty-one pregnant women with fetuses with intrauterine growth retardation and 27 normal pregnancies as controls. Correlation between amniotic fluid measurements of nitrite metabolite in the third trimester and flow velocimetry waveforms recorded from uterine, umbilical and fetal middle cerebral arteries. Intrauterine growth retarded pregnancies were compared with controls. Concentrations of nitric oxide metabolites (NO2- and NO3-) in amniotic fluid were correlated with flow velocimetry waveforms findings by the determination of correlation coefficient. Overall median nitrite values in amniotic fluid were higher (P < 0.01) in intrauterine growth retarded patients (median 8.6 micromol/mg creatinine) than in controls (5.6 micromol/mg creatinine). Pathologic uterine flow velocimetry waveforms in uterine artery (-2SD) were observed in 12 women of the intrauterine growth retarded group, and the concentration of amniotic fluid nitrite was significantly lower (P < 0.01) in these patients (median 4.45 micromol/mg creatinine) than in those with normal flow velocity waveforms (median 11.43 micromol/mg creatinine). A significant negative correlation was observed between nitrite concentrations and uterine artery resistance index, umbilical artery pulsatility index and umbilical artery pulsatility index:middle cerebral artery pulsatility index ratio. We conclude that placental nitric oxide is significantly associated with uteroplacental blood flow and may be important in maintaining adequate uteroplacental perfusion in intrauterine growth retarded pregnancies

    Transvaginal sonographic evaluation of endometrial polyps: A comparison with two dimensional and three dimensional contrast sonography

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    Endometrial polyps are a frequent cause of menorrhagia and are often associated with infertility. Routine transvaginal (TV) ultrasound evaluation may detect intrauterine anomalies. Sonographic evaluation of the endometrium after uterine cavity distention, called hystero-sono-salpingography (HSSG), improves the resolutive effectiveness of TV sonography. Recently the development of three-dimensional (3D) scanning of the uterine cavity has provided accurate images. The purpose of this study was to compare conventional 2D and 3D scanning of the uterine cavity with or without saline contrast medium in the detection and evaluation of focal endometrial polyps. Twenty-three patients out of 642 women suggestive for intrauterine anomalies at routine TV sonogram were examined by 2D and 3D sonography before and after intrauterine saline contrast medium. Sonographic appearance was verified by hysteroscopic and histologic evaluation. Two-dimensional TV sonography diagnosed 23 polyps versus 16 confirmed at hysteroscopic and histologic examinations, revealing a specificity of 69.5%; 2D TV HSSG diagnosed 17 polyps, with a specificity of 94.1%; 3D TV sonography diagnosed 18 polyps, with a specificity of 88.8%; 3D HSSG diagnosed 16 polyps according to hysteroscopic and histologic findings, with a specificity of 100%. HSSG has been demonstrated to be an effective and suitable method in the detection of intrauterine anomalies, particularly with 3D sonography
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