Remote-operated vehicle (ROV) valve operation

Author(s):  
Karan Sotoodeh
Keyword(s):  
2021 ◽  
Vol 147 (8) ◽  
pp. 04021046
Author(s):  
Bruno Brentan ◽  
Laura Monteiro ◽  
Joana Carneiro ◽  
Dídia Covas

2016 ◽  
Vol 69 (2) ◽  
Author(s):  
Z. Celebi Sözener ◽  
A. Kaya ◽  
C. Atasoy ◽  
M. Kılıckap ◽  
N. Numanoglu ◽  
...  

We present three cases of septic pulmonary embolism which occurred as a result of three different causes. The first case, was a 23 year old woman suffering from cough, sputum, hemopthisis and pleuritic chest pain. She had a right subclavian port. On her thorax computed tomography (CT) scans there were widespread bilateral, irregular parenchymal nodular infiltrates and some of them beginning to cavitate. Meticilin resistant stafilococus aureus (MRSA) was isolated from the blood culture and septic embolism was diagnosed. A month after antibiotic theraphy her parenchymal nodules have considerably decreased in size. The second case was a 40 year old woman admitted to our hospital with the same complaints. Her radiological findings were similar. Meticilin sensitive stafilococus aureus (MSSA) was isolated from the blood cultures and antibiotic theraphy was initiated. To investigate the etiology of the nodules due to septic embolism, echocardiography was performed and infective endocarditis was diagnosed. After the antibiotic theraphy and a tricuspid valve operation her parenchymal nodules disappeared. The final case involved a 51 year old man suffering from fever, fatigue, cough and pain in the left arm for one week. His general status was bad. His radiological findings were also similar to the others. Staphillococcus aureus was isolated from blood and wound culture. Following clinical and radiological findings we thought it was a case of septic pulmonary embolism and antibiotic theraphy was started. Despite the therapy we did not take fever response and he died five days after antibiotic therapy. In conclusion, septic pulmonary embolism should be considered in bilateral cavitary nodular infiltrates and must be managed fast.


2000 ◽  
Vol 30 (6) ◽  
pp. 737
Author(s):  
Young Min Eun ◽  
Jae Young Choi ◽  
Jong Kyun Lee ◽  
Jun Hee Sul ◽  
Seung Kyu Lee ◽  
...  

2021 ◽  
Vol 11 (19) ◽  
pp. 9252
Author(s):  
Claudia Patricia Durasiewicz ◽  
Sophia Thekla Güntner ◽  
Philipp Klaus Maier ◽  
Wolfgang Hölzl ◽  
Gabriele Schrag

Microfluidic systems for medical applications necessitate reliable, wide flow range, and low leakage microvalves for flow path control. High design complexity of microvalves increases the risk of possible malfunction. We present a normally open microvalve based on energy-efficient piezoelectric actuation for high closing forces and micromachined valve seat trenches for reliable valve operation. A comprehensive investigation of influencing parameters is performed by extensive fluidic 3D finite element simulation, derivation of an analytical closed state leakage rate model, as well as fabrication and test of the microvalve. Additional valve seat coating and a high force actuator are introduced for further leakage reduction. The microvalve has a wide-open flow range as well as good sealing abilities in closed state. Extensive fatigue tests of 1 × 106 actuation cycles show that additional coating of the valve seat or increased actuator strength promote sealing performance stability. Analytical calculations of leakage are suitable to estimate experimentally obtained leakage rates and, along with computational fluidic dynamic (CFD) simulations, enable future microvalve design optimization. In conclusion, we demonstrate that the presented normally open microvalve is suitable for the design of safe and reliable microfluidic devices for medical applications.


1992 ◽  
Vol 13 (5) ◽  
pp. 679-686 ◽  
Author(s):  
B. Hausen ◽  
H. von der Leyen ◽  
J. Vogelpohl ◽  
Ch. Dresler ◽  
B. Heublein ◽  
...  

Author(s):  
Alton Reich

In a pressurized water reactor the high pressure system vent lines from the pressurizer and reactor are routed to a common header that can be emptied to the refueling water storage tank or a drain tank. During plant testing the valves are operated in the following sequence: the pressurizer isolation valve is opened to pressurize the common header, the pressurizer isolation valve is closed, then the drain tank isolation valve is opened. This sequence of valve operation verifies that the valves open and close properly — opening the pressurizer isolation valve allows steam to enter the common header and is verified by pressure indication via a pressure transducer, and opening the drain tank isolation valve decreases the pressure in the common header and verifies that the pressurizer isolation valve closed properly. During this sequence of valve actuation, the other solenoid valves in the system are subject to transient steam pressures. During one test sequence an isolation valve to the refueling water storage tank indicated that it was not closed for a period of several seconds. Since there is only one pressure transducer in the common header, a systemlevel analysis was performed to obtain a more detailed understanding of the transient pressures in the common header, and how that might affect solenoid valve performance.


Author(s):  
Donald D. Glower ◽  
Bhargavi Desai

Objective The effects and benefits of a transaortic endoclamp for mitral valve operation through right minithoracotomy have not been established. Methods The records were examined in 671 patients undergoing mitral valve operation using aortic cannulation through a 6-cm right minithoracotomy in the fourth intercostal space. The ascending aorta was cannulated with a 24-Fr cannula through a 12-mm port in the first intercostal space. The experience from 1998 to 2006 with aortic endoclamping (group A, N = 436) was compared with the experience from 2006 to 2009 with external aortic clamping (group B, N = 235). Aortic endoclamping was achieved with a 30 mL endoclamp introduced through the aortic cannula into the ascending aorta to provide aortic endoclamping, anterograde cardioplegia, and root venting. Percutaneous femoral venous cannulation was used. Results Group A and group B had similar demographics. Endoclamp availability (group A) resulted in significantly less fibrillatory arrest (no clamping) in 67 of 436 (15%) versus 104 of 235 (44%) patients in group B (P = 0.001). In patients with aortic clamping, endoclamp (group A) versus external clamp (group B) was not a determinant of clamp time or pump time. Hospital and late outcomes were not different between groups. No patient complications could be attributed to the endoclamp. Conclusions Aortic endoclamping requires no more clamp or pump time than external clamping and can provide a more bloodless field than ventricular fibrillation without obstructing hardware. Aortic endoclamping is a safe alternative for mitral surgery through right minithoracotomy.


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