scholarly journals Alterations in time intervals of ductus venosus and atrioventricular flow velocity waveforms in growth-restricted fetuses

2015 ◽  
Vol 46 (2) ◽  
pp. 221-226 ◽  
Author(s):  
N. Wada ◽  
D. Tachibana ◽  
Y. Kurihara ◽  
K. Nakagawa ◽  
A. Nakano ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Ductus Venosus ◽  
Time Intervals

An Automatic Paperless Velocity Measuring and Recording System

2014 ◽  
Vol 889-890 ◽  
pp. 745-748
Author(s):  
Jian Sheng Cao ◽  
Wan Jun Zhang ◽  
Xin Hua Zeng
Keyword(s):  
Flow Velocity ◽  
Optical Pulse ◽  
Electric Pulse ◽  
Automatic Monitoring ◽  
Time Intervals ◽  
Stream Flows ◽  
Fluid Flow Velocity ◽  
Photoelectric Sensor ◽  
Velocity Measuring ◽  
Short Time

Automatic monitoring of hydrologic properties such as water velocity at short-time intervals is critical for understanding watershed eco-hydrological processes. This can also be used to study the laws of stream flows and interactions ecological process. The advent of modern electronic technology (and the near-perfection of especially sensor and data collection technologies), has made it possible to use automatic monitoring systems to continuously measure hydrologic properties at short-time intervals. This paper introduces one such paperless flow velocity measuring/recoding system. The system uses a photoelectric sensor that is mainly comprised of photoelectric velocity sensor and pulse recorder. The system uses propellers (with reflective panels and photoemission cells) to transform flow velocities into optical pulse signals. It also uses photosensitive tubes to transform optical pulse signals into electric pulse signals. The electric pulse counts (generated in unit time) are recorded via pulse recorders. This therefore accomplishes automatic monitoring and continuous recording of fluid flow velocity.

Ductus venosus flow velocity waveforms in relation to fetal behavioural states

1994 ◽  
Vol 101 (3) ◽  
pp. 220-224 ◽  
Author(s):  
Tjeerd W. A. Huisman ◽  
Christoph Brezinka ◽  
Patricia A. Stewart ◽  
Theo Stijnen ◽  
Juriy W. Wladimiroff
Keyword(s):  
Flow Velocity ◽  
Ductus Venosus

Reference ranges for time-related analysis of ductus venosus flow velocity waveforms in singleton pregnancies

2012 ◽  
Vol 32 (8) ◽  
pp. 803-809 ◽  
Author(s):  
Kayoko Nakagawa ◽  
Daisuke Tachibana ◽  
Hiroyuki Nobeyama ◽  
Mitsuru Fukui ◽  
Toshiyuki Sumi ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Ductus Venosus ◽  
Reference Ranges ◽  
Singleton Pregnancies

375: Ductus venosus flow velocity waveforms indices and arterial cord pH in IUGR fetuses delivered at 32 weeks

2009 ◽  
Vol 201 (6) ◽  
pp. S145
Author(s):  
Juan De Leon-Luis ◽  
Giancarlo Mari ◽  
Jacques Samson ◽  
Robert Egerman ◽  
Yinka Oyelese ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Ductus Venosus

scholarly journals Relevance of measuring diastolic time intervals in the ductus venosus during the early stages of twin–twin transfusion syndrome

2007 ◽  
Vol 30 (7) ◽  
pp. 983-987 ◽  
Author(s):  
B. Bensouda ◽  
J.-C. Fouron ◽  
M.-J. Raboisson ◽  
J. Lamoureux ◽  
C. Lachance ◽  
...  
Keyword(s):  
Ductus Venosus ◽  
Time Intervals ◽  
Early Stages ◽  
Diastolic Time

Prediction of Twin-to-Twin Transfusion Syndrome Using Characteristic Waveforms of Ductus Venosus in Recipient Twins

2020 ◽  
Vol 23 (5) ◽  
pp. 292-297
Author(s):  
Mayumi Takano ◽  
Masahiko Nakata ◽  
Sumito Nagasaki ◽  
Junya Sakuma ◽  
Mineto Morita
Keyword(s):  
Predictive Value ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Curve Analysis ◽  
Ductus Venosus ◽  
Second Trimester ◽  
S Wave ◽  
Time Intervals ◽  
Doppler Flow ◽  
Twin Pregnancies

AbstractWe aimed to investigate whether the alterations of time intervals and velocity–time integrals (VTIs) of ductus venosus (DV) Doppler flow could predict evolving twin-to-twin transfusion syndrome (TTTS) in monochorionic diamniotic (MD) twin pregnancies in the second trimester. DV Doppler waveforms of MD twin pregnancies were retrospectively analyzed. Time intervals and VTIs of the accelerating phase of S-wave (S1 and VTI-1), decelerating phase of S-wave (S2 and VTI-2) and phase of D-wave (D and VTI-diast) were measured in the recipient twins of TTTS and the larger twins of uncomplicated MD twins. Each parameter was normalized to total time intervals and VTIs. DV parameters of prerecipient twins in pre-TTTS conditions were analyzed. The pre-TTTS condition was defined as the condition within 2 weeks before when TTTS cases fulfilled the criteria. Both recipient twins in TTTS cases and prerecipient twins in pre-TTTS condition showed significantly shorter S1, longer S2, shorter D, smaller VTI-1, larger VTI-2 and smaller VTI-diast than did the larger twins in uncomplicated MD twins (p < .05). Receiver-operating characteristic curve analysis showed that VTI-2 had better performance, and VTI-2 >45.5% had 87.0% sensitivity, 90.9% specificity, 81.0% positive predictive value and 93.0% negative predictive value for detecting prerecipient twins. Recipient twins complicated with TTTS have characteristic alterations in time intervals and VTIs of DV Doppler flow, which is present even before fulfilling the TTTS criteria. Furthermore, VTI-2 >45.5% is a possible predictive parameter for TTTS in the second trimester.

scholarly journals Ductus Venosus Doppler Flow Velocity after Transplacental and Non-transplacental Amniocentesis during Midtrimester

1969 ◽  
Vol 30 (5) ◽  
Author(s):  
Burcu Artunc Ulkumen ◽  
Halil Gursoy Pala ◽  
Yesim Bulbul Baytur ◽  
Faik Mumtaz Koyuncu
Keyword(s):  
Flow Velocity ◽  
Ductus Venosus ◽  
Doppler Flow
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