FRACTAL MODEL OF BLOOD VESSEL SYSTEM

Fractals ◽  
1993 ◽  
Vol 01 (02) ◽  
pp. 191-197 ◽  
Author(s):  
JAAN KALDA
Keyword(s):  
Blood Pressure ◽  
Blood Vessel ◽  
Oxygen Supply ◽  
Average Diameter ◽  
Spatial Arrangement ◽  
Fractal Model ◽  
Statistical Characteristics ◽  
Generation Number ◽  
Self Similar

A possible way of modeling of self-similar biological tree-like structures is proposed. Special attention is paid to the blood-vessel system, with elaboration on a model with certain spatial arrangement of the vessels and reasonable dependence of the blood pressure on the vessels diameter, such that the organism has a homogeneous oxygen supply. A model of the lung is also presented, which reproduces a qualitatively right dependence of the average diameter of the tubes on their generation number. The model of the blood-vessel system is based on suitably generalized Scheidegger’s model of rivers. The statistical characteristics of the modified Scheidegger’s model are established.

COMPARISON OF ANTIHYPERTENSIVE EFFECT OF MOXONIDINE VERSUS CLONIDINE IN RENAL FAILURE PATIENTS.

2018 ◽  
Vol 6 (9) ◽  
Author(s):  
DR.MATHEW GEORGE ◽  
DR.LINCY JOSEPH ◽  
MRS.DEEPTHI MATHEW ◽  
ALISHA MARIA SHAJI ◽  
BIJI JOSEPH ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Failure ◽  
Blood Flow ◽  
Blood Vessel ◽  
Blood Vessels ◽  
High Blood Pressure ◽  
Antihypertensive Effect ◽  
The Body ◽  
Ability To Work ◽  
Blood Flows

Blood pressure is the force of blood pushing against blood vessel walls as the heart pumps out blood, and high blood pressure, also called hypertension, is an increase in the amount of force that blood places on blood vessels as it moves through the body. Factors that can increase this force include higher blood volume due to extra fluid in the blood and blood vessels that are narrow, stiff, or clogged(1). High blood pressure can damage blood vessels in the kidneys, reducing their ability to work properly. When the force of blood flow is high, blood vessels stretch so blood flows more easily. Eventually, this stretching scars and weakens blood vessels throughout the body, including those in the kidneys.

Bio-Medico-Mechanical Behavior of Natural Artery Blood Vessel Under Constant and Variable Internal Pulsatile Pressure Flow Test In Vitro

1986 ◽  
Vol 108 (4) ◽  
pp. 295-300 ◽  
Author(s):  
A. T. Yokobori ◽  
T. Maeyama ◽  
T. Ohkuma ◽  
T. Yokobori ◽  
H. Ohuchi ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Vessel ◽  
Mechanical Behavior ◽  
Arterial System ◽  
Pressure Amplitude ◽  
Constant Amplitude ◽  
Pressure Flow ◽  
Fluctuating Pressure ◽  
Pulsatile Pressure

Studies have been carried out on the bio-medico-mechanical behavior in vitro of natural blood vessel (dogs) under constant and variable internal pulsatile pressure flow. The apparatus designed by us well simulated the arterial system. The studies were made for the case of pressure amplitude kept as constant, of the two-step-multi-duplicated pulsatile pressure and of the fluctuating pressure. For the case of the fluctuating pressure, the strength of the artery becomes considerably lower than those under constant amplitude and two-step-multi-duplicated pulsatile pressure. SEM observations of the inner walls of the artery shows that collagen fibers are more elongated under fluctuating pulsatile pressure flow. In conclusion, in order to avoid the mechanical deterioration of the artery strength, it is useful to keep the pulsatile blood pressure at constant amplitude. Even for the case of the blood pressure fluctuation, it is necessary to manage to keep the blood pressure as near a regular wave as possible, the total number of repeated pulse being equal.

Activation of Peripheral Opioid µ-Receptors in Blood Vessel May Lower Blood Pressure in Spontaneously Hypertensive Rats

Pharmacology ◽  
2011 ◽  
Vol 87 (5-6) ◽  
pp. 257-264 ◽  
Author(s):  
Zhih-Cherng Chen ◽  
Ja-Ping Shieh ◽  
Hsien-Hui Chung ◽  
Ching-Hsia Hung ◽  
Hung Jung Lin ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Vessel ◽  
Spontaneously Hypertensive Rats ◽  
Lower Blood Pressure ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Lower Blood

A FRACTAL SCALING LAW BETWEEN TORTUOSITY AND POROSITY IN POROUS MEDIA

Fractals ◽  
2020 ◽  
Vol 28 (02) ◽  
pp. 2050025
Author(s):  
PENG XU ◽  
LIPEI ZHANG ◽  
BINQI RAO ◽  
SHUXIA QIU ◽  
YUQING SHEN ◽  
...  
Keyword(s):  
Porous Media ◽  
Chemical Engineering ◽  
Oil And Gas ◽  
Scaling Law ◽  
Morphological Characteristics ◽  
Fractal Model ◽  
Statistical Characteristics ◽  
Scale Model ◽  
Reservoir Water ◽  
Flow Through

Hydraulic tortuosity is one of the key parameters for evaluating effective transport properties of natural and artificial porous media. A pore-scale model is developed for fluid flow through porous media based on fractal geometry, and a novel analytical tortuosity–porosity correlation is presented. Numerical simulations are also performed on two-dimensional Sierpinski carpet model. The proposed fractal model is validated by comparison with numerical results and available experimental data. Results show that hydraulic tortuosity depends on both statistical and morphological characteristics of porous media. The exponents for the scaling law between tortuosity and porosity depend on pore size distribution and tortuous fractal dimension. It has been found that hydraulic tortuosity indicates evident anisotropy for asymmetrical particle arrangements under the same statistical characteristics of porous media. The present work may be helpful to understand the transport mechanisms of porous materials and provide guidelines for the development of oil and gas reservoir, water resource and chemical engineering, etc.

scholarly journals The Effect of Silver Nanofibers on the Deformation Properties of Blood Vessels: Towards the Development of New Nanotechnologies to Prevent Rupture of Aneurysms

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Miguel Gonzalez ◽  
Daniel Rivera ◽  
Alam Marcelino ◽  
Gabriela Agront ◽  
Rafael Rodriguez ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Vessel ◽  
Mechanical Stress ◽  
Blood Vessels ◽  
Human Body ◽  
Clinical Setting ◽  
Failure Strength ◽  
Clinical Tool ◽  
Deformation Properties ◽  
Clinically Significant

An aneurysm is the result of a widening or ballooning of a portion of a blood vessel. The rupture of an aneurysm occurs when the mechanical stress acting on the inner wall exceeds the failure strength of the blood vessel. We propose an innovative approach to prevent the rupture of an aneurysm based on the use of nanotechnology to improve the strength of the blood vessel. We present results on the effect of silver nanofibers on the resistance toward deformation of blood vessels. The silver nanofibers are grown on the surface of the blood vessels. The nanofibers are120±30 nm in diameter and2.7±0.8 μm in length. The deformation per applied force of blood vessels was found to decrease from 0.15 m/N in control blood vessels to 0.003 m/N in blood vessels treated with the nanofibers. This represents an increase in the resistance towards deformation of a factor of 50. The increase in the resistance towards deformation is clinically significant since blood pressure increases by factors slightly larger than one in the human body. Treatment of blood vessels with silver nanofibers is a potential translational clinical tool for preventing rupture of aneurysms in a clinical setting.

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