scholarly journals Simultaneous Control of Speed and Thrust of Hydraulic Actuator with Magnetorheological Fluids Valve Using Rectangular Pulse Wave Control

2020 ◽  
Vol 51 (2) ◽  
pp. 32-38
Author(s):  
Nobuo OSHIMA ◽  
Masaya FUKUDA ◽  
Yuhei SHIMIZU
Keyword(s):  
Pulse Wave ◽  
Rectangular Pulse ◽  
Magnetorheological Fluids ◽  
Hydraulic Actuator ◽  
Simultaneous Control ◽  
Wave Control

Arterial stiffness is a potential mechanism and promising indicator of orthostatic hypotension in the general population

VASA ◽  
2014 ◽  
Vol 43 (6) ◽  
pp. 423-432 ◽  
Author(s):  
Qingtao Meng ◽  
Si Wang ◽  
Yong Wang ◽  
Shixi Wan ◽  
Kai Liu ◽  
...  
Keyword(s):  
General Population ◽  
Arterial Stiffness ◽  
Orthostatic Hypotension ◽  
Operating Characteristic ◽  
Pulse Wave ◽  
Augmentation Index ◽  
Multiple Logistic Regression Analysis ◽  
The Elderly ◽  
Baroreceptor Sensitivity ◽  
Roc Curve Analysis

Background: Orthostatic hypotension (OH) is a disease prevalent among middle-aged men and the elderly. The association between arterial stiffness and OH is unclear. This study evaluates whether arterial stiffness is correlated with OH and tests the usefulness of brachial-ankle pulse wave velocity (baPWV), an arterial stiffness marker, with regard to identifying OH. Patients and methods: A sample of 1,010 participants was recruited from the general population (64.8 ± 7.7 years; 426 men) who attended health check-ups. BaPWV and the radial augmentation index (rAI) were both assessed as the arterial stiffness markers, and OH was determined using blood pressure (BP) measured in the supine position, as well as 30 seconds and 2 minutes after standing. Results: The prevalence of OH in this population was 4.9 %. Compared with the non-OH group, both baPWV (20.5 ± 4.5 vs 17.3 ± 3.7, p < 0.001) and rAI (88.1 ± 10.8 vs 84.2 ± 10.7, p < 0.05) were significantly higher in the OH group. In the multiple logistic regression analysis, baPWV (OR, 1.3; 95 % CI, 1.106–1.528; p < 0.05) remained associated with OH. Moreover, the degree of orthostatic BP reduction was related to arterial stiffness. In addition, increases in arterial stiffness predicted decreases in the degree of heart rate (HR) elevation. Finally, a receiver operating characteristic (ROC) curve analysis showed that baPWV was useful in discriminating OH (AUC, 0.721; p < 0.001), with the cut-off value of 18.58 m/s (sensitivity, 0.714; specificity, 0.686). Conclusions: Arterial stiffness determined via baPWV, rather than rAI, was significantly correlated with the attenuation of the orthostatic hemodynamic response and the resultant OH. The impaired baroreceptor sensitivity might be the mechanism. In addition, baPWV appears to be a relatively sensitive and reliable indicator of OH in routine clinical practice.

Markers of arterial stiffness in peripheral arterial disease

VASA ◽  
2015 ◽  
Vol 44 (5) ◽  
pp. 341-348 ◽  
Author(s):  
Marc Husmann ◽  
Vincenzo Jacomella ◽  
Christoph Thalhammer ◽  
Beatrice R. Amann-Vesti
Keyword(s):  
Arterial Stiffness ◽  
Peripheral Arterial Disease ◽  
Pulse Wave ◽  
Augmentation Index ◽  
Arterial Disease ◽  
Care Physician ◽  
Additional Information ◽  
Non Invasive ◽  
Assessment Techniques ◽  
Peripheral Arterial

Abstract. Increased arterial stiffness results from reduced elasticity of the arterial wall and is an independent predictor for cardiovascular risk. The gold standard for assessment of arterial stiffness is the carotid-femoral pulse wave velocity. Other parameters such as central aortic pulse pressure and aortic augmentation index are indirect, surrogate markers of arterial stiffness, but provide additional information on the characteristics of wave reflection. Peripheral arterial disease (PAD) is characterised by its association with systolic hypertension, increased arterial stiffness, disturbed wave reflexion and prognosis depending on ankle-brachial pressure index. This review summarises the physiology of pulse wave propagation and reflection and its changes due to aging and atherosclerosis. We discuss different non-invasive assessment techniques and highlight the importance of the understanding of arterial pulse wave analysis for each vascular specialist and primary care physician alike in the context of PAD.

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.

Augmentation Index und Pulse Wave Velocity in Schwangerschaften mit Präeklampsie oder Gestationsdiabetes

2007 ◽  
Vol 211 (S 2) ◽  
Author(s):  
B Schiessl ◽  
M Burgmann ◽  
V Sauer ◽  
A Neubauer ◽  
F Kainer ◽  
...  
Keyword(s):  
Pulse Wave Velocity ◽  
Wave Velocity ◽  
Pulse Wave ◽  
Augmentation Index

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

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