scholarly journals Theoretical Modelling of Alveolar Resonance Mechanism of Ultrasound-Induced Lung Haemorrhage

2012 ◽  
Vol 18 (2) ◽  
pp. 59-71 ◽  
Author(s):  
D. John Jabaraj ◽  
Mohamad Suhaimi Jaafar
Keyword(s):  
Vibration Analysis ◽  
Ultrasound Examination ◽  
Theoretical Modelling ◽  
Alveolar Wall ◽  
Mechanical Index ◽  
Threshold Pressure ◽  
Resonance Mechanism ◽  
Adult Human ◽  
Ultrasound Frequency ◽  
Lung Haemorrhage

The possibility of the ultrasound-induced lung haemorrhage occurring in adult human during diagnostic ultrasound examination is studied here. This study is based on the hypothetical alveolar resonance mechanism of the ultrasound-induced lung haemorrhage. The alveolar wall is initially modelled here as a square membrane with fixed-boundary, and then theoretically subjected to vibration analysis. The equation of threshold pressure for the occurrence of ultrasound-induced lung haemorrhage is derived. A comparison test against past experimental data validates the use of the square membrane model of the alveolar wall in studying the ultrasound induced lung haemorrhage. This study predicts that the ultrasound-induced lung haemorrhage in adult human can be prevented if the ultrasound frequency is kept above 1.69 MHz while the Mechanical Index does not exceed 1.9.

scholarly journals Canine Fetal Peritonitis

2017 ◽  
Vol 45 ◽  
pp. 4
Author(s):  
Andreia Regis De Assis ◽  
Marcus Antonio Rossi Feliciano ◽  
Gilberto Gonçalves Facco ◽  
Patricia Eri Ishii ◽  
Cláudia Matsunaga Martin ◽  
...  
Keyword(s):  
Mucous Membrane ◽  
Ultrasound Examination ◽  
Abdominal Cavity ◽  
Intestinal Loop ◽  
Alveolar Wall ◽  
Neonatal Deaths ◽  
Gestational Period ◽  
Clinical Complications ◽  
Cytological Smear ◽  
Vascular Congestion

Background: The occurrence of neonatal diseases and neonatal deaths in canines are considered higher in the first days of life of individuals and bacterial diseases are considered the second most common cause. Inflammation of the mesothelial lining of the abdominal cavity is referred peritonitis, which can be classified as primary or secondary and there is no description on the occurrence of canine fetal peritonitis in the veterinary literature. The objective of this study is to describe a case of canine fetus peritonitis, presenting abnormal sonographic findings of the fetus and abnormalities identified after birth that were not yet described in veterinary literature.Case: A female Poodle, six years of age, considered healthy and without clinical complications during the gestational period, was referred for sonographic evaluation at the end of the pregnancy, in order to evaluate of the fetal viability and estimate the gestational period. By ultrasound examination, two canine fetuses were identified and based on its morphogenesis and biparietal diameter, the estimated gestational age was approximately 58 days. On the individual examination of each of the fetus by ultrasound, it was found that one of them had normal sonographic findings and on the second canine fetus it was found an increase of the intra-abdominal echogenicity of tissues, loss of the sonographic definition of the intestinal loops and presence of laminar anechoic areas between the interfaces of organs, consistent with abdominal effusion. Parturition occurred the following day of the ultrasound examination no complications and with the birth of two canine fetuses. About six hours after birth, one of the neonates showed dyspnea, hypothermia, areas of ecchymosis, suffusion in the ventral abdominal region, icteric and pale mucous membrane and the presence of abdominal fluid and came to death about 30 min after. Cytological analysis of the sample revealed exuberant amount of erythrocytes, fibrin and leukocytes. Culture revealed infection by Staphylococccus aureus and Enterococcus sp. Presence of bloody fluid in the abdominal cavity was observed at necropsy, with yellowish parietal surface of the thoracic and abdominal cavities and petechiae on the lungs, heart, stomach surfaces and intestinal mucous membrane. Microscopically, the lungs showed extensive areas of parenchymal consolidation, vascular congestion and intense inflammatory infiltrate in the alveolar wall; the liver was characterized by vascular congestion, areas of degeneration of hepatocytes and presence of calcified foci, necrosis and inflammatory infiltrates. Associating the results and findings of the exams was possible to conclude the diagnostic of fetal peritonitis.Discussion: The visualization of abnormal findings in affected fetus by a gestational ultrasound exam makes this report inedited and relevant for veterinary obstetrics. This demonstrates the importance of ultrasound exam in pregnant bitches for early detection of maternal fetal diseases. Presence of abdominal fluid and increased mesenteric ochogenicity associated with loss of the intestinal loop definition corroborates with the clinical suspicion of peritonitis in fetus. Findings on the anatomopathological examination, cytology and culture allowed conclusion of the cause of death. Bacterial forms in the cytological smear supported the diagnostic suspicion of peritonitis. Gestational ultrasound exam performed in this report was essential for proper conduct of the pregnant bitch and viability of the fetuses, suggesting that the detected fetal abnormalities showed predictive value in the viability of diseased individual. This case report contributes with the description of canine fetal peritonitis.

Space-time visualization of vibration of a ribbed cylinder

2000 ◽  
Vol 214 (10) ◽  
pp. 1259-1271 ◽  
Author(s):  
J Woodhouse ◽  
J Power
Keyword(s):  
Frequency Analysis ◽  
Cross Sections ◽  
Vibration Analysis ◽  
Experimental Approach ◽  
Space Time ◽  
Theoretical Modelling ◽  
Time Frequency Analysis ◽  
Time Frequency ◽  
Vibrational Response ◽  
Engineering Vibration

Data from an axial array of sensors along a ribbed cylindrical structure may be analysed to allow the evolving vibrational response to impulsive driving to be plotted as a function of space and time. The process is carried out separately in a series of frequency bands, by first carrying out a time-frequency analysis at each position. Aspects of the behaviour not previously discussed are highlighted by this analysis. These aspects are discussed in the light of a previously published theoretical model [1]. Since reflections from the cylinder's ends also play a role here, it has been necessary to develop further theoretical modelling to interpret the measurements. The new experimental approach, which is described here as the method of ‘space-time cross-sections', has scope for application to other problems involving structure-borne vibration. This illustrates the power of time-frequency analysis and its extensions for engineering vibration analysis.

scholarly journals CALCULATION OF A SONOCAPILLARY EFFECT DEPENDENCE ON AN ULTRASONIC FREQUENCY BASED ON A THRESHOLD CAVITATION CRITERION

2020 ◽  
Vol 82 (1) ◽  
pp. 64-74
Author(s):  
N.V. Mikhailova ◽  
I.V. Smirnov ◽  
A. Sharipova ◽  
V. Slesarenko
Keyword(s):  
Experimental Data ◽  
Capillary Pressure ◽  
Process Zone ◽  
Ultrasonic Frequency ◽  
Threshold Pressure ◽  
Acoustic Vibrations ◽  
Capillary Effect ◽  
Frequency Range ◽  
Ultrasound Frequency ◽  
Cavitation Bubbles

The possibility of calculating parameters of the ultrasonic capillary effect depending on frequency of acoustic vibrations in liquid is considered. According to known experimental data, the intensification of fluid motion in the capillary is mainly associated with the formation and collapse of cavitation bubbles at the capillary end. Therefore, it is assumed that the ultrasonic capillary effect occurs as a result of cavitation processes at the entrance to the capillary channel, while cavitation processes depend on the frequency of ultrasonic vibrations. The threshold pressure at cavitation, leading to the rise of fluid, for a given ultrasound frequency is determined by the criterion of incubation time of cavitation. The size and number of cavitation bubbles at the considered threshold pressure depend on ultrasound frequency. The number of bubbles in the cavitation area is determined by solving the problem of packing equal circles in a larger circle, taking into account the distance the influence of the bubbles on each other. The height of the liquid rise is calculated based on the assumption that during one cycle of oscillation of the cavitation region, the sound capillary pressure performs the work on lifting the liquid column to a certain height due to the energy of collapsed bubbles. This approach makes it possible to determine the threshold amplitude of acoustic vibrations and evaluate the corresponding behaviour of sound-capillary pressure in the frequency range of 7-62 kHz. The specified range is determined by the frequency requirements for the ratio of the size of the cavitation process zone and the capillary diameter. Thus, the obtained model of the ultrasonic capillary effect takes into account the diameter of the capillary and allows to determine the frequency range over which this effect can be realized. The calculation results show good agreement with the known experimental data in water. The results of calculations using the model showed that the highest sound capillary pressure is reached in the range of 10-20 kHz.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

Immunohistochemical studies on 3β-hydroxysteroid dehydrogenase in the adult human adrenal

1998 ◽  
Vol 5 (1) ◽  
pp. 94A-94A
Author(s):  
R MIXON ◽  
R BRISSIE ◽  
W GRIZZLE ◽  
J THOMAS ◽  
O FAYEPELERSEN ◽  
...  
Keyword(s):  
Hydroxysteroid Dehydrogenase ◽  
Adult Human ◽  
Immunohistochemical Studies

Modulation of carotid strain by statin therapy in atherosclerosis patients

VASA ◽  
2017 ◽  
Vol 46 (2) ◽  
pp. 108-115 ◽  
Author(s):  
Christian Alexander Schaefer ◽  
Anna Katharina Blatzheim ◽  
Sebastian Gorgonius Passon ◽  
Kristin Solveig Pausewang ◽  
Nadjib Schahab ◽  
...  
Keyword(s):  
Statin Therapy ◽  
Pulse Wave ◽  
Ultrasound Examination ◽  
Ankle Brachial Index ◽  
Radial Strain ◽  
Strain Analysis ◽  
Duplex Ultrasound ◽  
Strain Imaging ◽  
The Common

Abstract. Background: The beneficial effect of statin therapy on the progress of atherosclerotic disease has been demonstrated by numerous studies. Vascular strain imaging is an arising method to evaluate arterial stiffness. Our study examined whether an influence of statin therapy on the vessel wall could be detected by vascular strain imaging. Patients and methods: 88 patients with recently detected atherosclerosis underwent an angiological examination including ankle-brachial index (ABI), pulse wave index (PWI), central puls ewave velocity and duplex ultrasound. Captures for vascular strain analysis were taken in B-mode during ultrasound examination of the common carotid artery and evaluated using a workstation equipped with a speckle tracking based software. A statin therapy was recommended and after six months a follow-up examination took place. Meanwhile, the non-adherence of a group of patients (N = 18) lead to a possibility to observe statin effects on the vascular strain. Results: In the statin non-adherent group the ABI decreased significantly to a still non-pathological level (1.2 ± 0.2 vs. 1.0 ± 0.2; p = 0.016) whereas it stagnated in the adherent group (1.0 ± 0.2 vs. 1.0 ± 0.2; p = 0.383). The PWI did not differ in the non-adherent group (180.5 ± 71.9 vs. 164.4 ± 75.8; p = 0.436) but under statin therapy it decreased significantly (261.8 ± 238.6 vs. 196.4 ± 137.4; p = 0.016). In comparison to the adherent group (4.2 ± 2.0 vs. 4.0 ± 1.8; p = 0.548) under statin therapy the radial strain decreased significantly in the non-adherent group (4.7 ± 2.0 vs. 3.3 ± 1.1; p = 0.014). Conclusions: Our findings reveal a beneficial influence of statin therapy on the arterial wall detected by vascular strain analysis.

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