نتایج جستجو برای: pulse wave

تعداد نتایج: 297106  

Journal: :Hypertension 2008
Berend E Westerhof Jeroen P van den Wijngaard Joseph P Murgo Nicolaas Westerhof

Aortic pulse wave velocity (PWV), a measure of aortic stiffness, is an important indicator of cardiovascular risk. Derivation of PWV from uncalibrated proximal aortic or carotid pressure alone has practical advantages. However, when the time of return of the reflected wave, (Delta)t, is used to calculate PWV, inaccurate data are obtained. With aging PWV increases but (Delta)t hardly decreases, ...

Journal: :The Japanese journal of physiology 2003
Jun Sugawara Takeshi Otsuki Takumi Tanabe Seiji Maeda Shinya Kuno Ryuichi Ajisaka Mitsuo Matsuda

We examined the effect of low-intensity single-leg exercise (20 or 30 watt, 5 min) on pulse wave velocity from the femoral to the ankle arteries in 18 young men. After the exercise, the velocity significantly decreased in the exercised leg, but not in the counterpart, suggesting that the decrease in arterial stiffness in the exercised leg was induced mainly by exercise-related regional factors.

Journal: :J. Comb. Theory, Ser. A 1974
Richard J. Turyn

If a Williamson matrix of order 4w exists and a special type of design, a set of Baumert-Hall units of order 4t, exists, then there exists a Hadamard matrix of order 4tw. A number of special Baumert-Hall sets of units, including an infinite class, are constructed here; these give the densest known classes of Hadamard matrices. The constructions relate to various topics such as pulse compression...

2018
Luca Gabutti Rosaria Del Giorno

and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, pleas...

Journal: :Hypertension 2008
Shari R Waldstein S Carrington Rice Julian F Thayer Samer S Najjar Angelo Scuteri Alan B Zonderman

Pulse pressure and pulse wave velocity, markers of arterial stiffness, have been associated with stroke, dementia, and lowered levels of cognitive function. Here we examine longitudinal relations of pulse pressure and pulse wave velocity to multiple domains of cognitive function among nondemented, stroke-free persons. Up to 1749 participants from the Baltimore Longitudinal Study of Aging comple...

2012
Lee Stoner Joanna M. Young Simon Fryer

Conventionally, the assessments of endothelial function and arterial stiffness require different sets of equipment, making the inclusion of both tests impractical for clinical and epidemiological studies. Pulse wave analysis (PWA) provides useful information regarding the mechanical properties of the arterial tree and can also be used to assess endothelial function. PWA is a simple, valid, reli...

1998
Argyrios A. Chatzipetros Amr M. Shaarawi Mohamed A. Abdel-Rahman

The feasibility of exciting a localized X-wave pulse from a finite aperture is addressed. Also, the possibility of using a finite-time excitation of a dynamic aperture to generate a finite-energy approximation to an X-wave pulse is explored. The analysis is carried out by using a Gaussian time window to time limit the infinite X-wave initial excitation. Huygens’ construction is used to calculat...

Journal: :Hypertension 2001
R P Kelly S C Millasseau J M Ritter P J Chowienczyk

Aortic augmentation index, a measure of central systolic blood pressure augmentation arising mainly from pressure-wave reflection, increases with vascular aging. The augmentation index is influenced by aortic pulse-wave velocity (related to aortic stiffness) and by the site and extent of wave reflection. To clarify the relative influence of pulse-wave velocity and wave reflection on the augment...

2012
Keisuke Takashima Igor V. Adamovich Uwe Czarnetzki Dirk Luggenhölscher

Positive and negative polarity fast ionization wave discharges in nitrogen and dry air are studied in a rectangular geometry channel over a wide range of time delays between the discharge pulses, s = 10 ms to 25 ls (pulse repetition rates of m = 100 Hz– 40 kHz). The discharge is generated by alternating polarity high-voltage pulses (peak voltage 18–23 kV, pulse duration 50–60 ns). Ionization wa...

Journal: :Hypertension 2006
Sola Aoun Bahous Antoine Stephan Jacques Blacher Michel E Safar

In subjects with renal disease, reduced renal function and increased arterial stiffness are significantly associated in cross-sectional studies. The relationship is independent of age, blood pressure (BP), and atherosclerosis. Because both variables are independent predictors of cardiovascular risk, time-dependent relationships between them are important to determine. Aortic pulse wave velocity...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید