A blood vessel exposed to ultrasound: A mathematical simulation of the temperature field

2002 ◽  
Vol 111 (3) ◽  
pp. 1454-1459 ◽  
Author(s):  
Boris Krasovitski ◽  
Eitan Kimmel
Keyword(s):  
Temperature Field ◽  
Blood Vessel ◽  
Mathematical Simulation

scholarly journals Modeling of temperature field inside the tissue with a blood vessel using the BEM-FDM algorithm

2012 ◽  
Vol 11 (4) ◽  
pp. 85-92
Author(s):  
Ewa Majchrzak ◽  
◽  
Jolanta Borowska ◽  
Joanna Klekot ◽  
Damian Tarasek ◽  
...  
Keyword(s):  
Temperature Field ◽  
Blood Vessel

Effect of blood vessel locations on HIFU temperature field: A simulation study

2010 ◽  
Author(s):  
Ping Zhang ◽  
Wujun Sun ◽  
Yuanguang Zhu ◽  
Xiaojing Zhang ◽  
Mizuo Zhang ◽  
...  
Keyword(s):  
Temperature Field ◽  
Blood Vessel ◽  
Simulation Study

Theoretical Analysis of the Large Blood Vessel Influence on the Local Tissue Temperature Decay After Pulse Heating

1993 ◽  
Vol 115 (2) ◽  
pp. 175-179 ◽  
Author(s):  
L. X. Xu ◽  
M. M. Chen ◽  
K. R. Holmes ◽  
H. Arkin
Keyword(s):  
Temperature Field ◽  
Blood Vessel ◽  
Point Source ◽  
Blood Perfusion ◽  
Tissue Temperature ◽  
Surrounding Tissue ◽  
Heating Pulse ◽  
Local Tissue ◽  
Large Blood Vessel ◽  
Temperature Decay

The influence of a large blood vessel (larger than 500 μm in diameter) on the local tissue temperature decay following a point source heating pulse was determined numerically using a sink/source method. It was assumed that the vessel was large enough so that the temperature of blood flowing within it remained essentially constant and was unaffected by any local tissue temperature transients. After the insertion of a point source heating pulse, the vessel influence on the local tissue transient temperature field was estimated by representing the vessel as a set of negative fictitious instantaneous heat sources with strength just sufficient to maintain the vessel at a constant temperature. In the surrounding tissue, the Pennes’ tissue heat transfer equation was used to describe the temperature field. Computations have been performed for a range of vessel sizes, probe-vessel spacings and local blood perfusion rates. It was found that the influence of a large vessel on the local tissue temperature decay is more sensitive to its size and location rather than to the local blood perfusion rate. For a heating pulse of 3s duration and 5 mW of power, there is a critical probe-vessel center distance 7R (R, vessel radius) beyond which the larger vessel influence on tissue temperature at the probe can be neglected.

An Ultrastructural Study of Pericytes

1968 ◽  
Vol 26 ◽  
pp. 66-67
Author(s):  
T. M. Murad ◽  
E. von Haam
Keyword(s):  
Plasma Membrane ◽  
Endothelial Cell ◽  
Basement Membrane ◽  
Blood Vessel ◽  
Vascular Endothelial Cells ◽  
Myoepithelial Cells ◽  
Capillary Blood ◽  
The Body ◽  
Capillary Blood Vessel ◽  
Outer Plasma Membrane

Pericytes are vascular satellites present around capillary blood vessels and small venules. They have been observed in almost every tissue of the body and are thought to be related to vascular smooth muscle cells. Morphologically pericytes have great similarity to vascular endothelial cells and also slightly resemble myoepithelial cells.The present study describes the ultrastructural morphology of pericytes in normal breast tissue and in benign tumor of the breast. The study showed that pericytes are ovoid or elongated cells separated from the endothelial cell of the capillary blood vessel by the basement membrane of endothelial cell. The nuclei of pericytes are often very distinctive. Although some are round, oval, or elongated, others show marked irregularity and infolding of the nuclear membrane. The cytoplasm shows mono-or bipolar extension in which the cytoplasmic organelles are located (Fig. 1). These cytoplasmic extensions embrace the capillary blood vessel incompletely. The plasma membrane exhibits multiple areas of focal condensation called hemidesmosomes (Fig. 2, arrow). A variable number of pinocytotic vesicles are frequently seen lining the outer plasma membrane. Normally pericytes are surrounded by a basement membrane which is found more consistently on the outer plasma membrane separating the pericytes from the stromal connective tissue.

Characteristics and Application of Temperature-Field Emitters

1975 ◽  
Vol 33 ◽  
pp. 144-145
Author(s):  
N. Tamura ◽  
T. Goto ◽  
Y. Harada
Keyword(s):  
Temperature Field ◽  
Electron Microscope ◽  
Field Emission ◽  
Resolving Power ◽  
High Brightness ◽  
Field Emitters ◽  
Emission Electron ◽  
Sufficient Stability ◽  
Scanning Electron ◽  
Illuminating System

On account of its high brightness, the field emission electron source has the advantage that it provides the conventional electron microscope with highly coherent illuminating system and that it directly improves the, resolving power of the scanning electron microscope. The present authors have reported some results obtained with a 100 kV field emission electron microscope.It has been proven, furthermore, that the tungsten emitter as a temperature field emission source can be utilized with a sufficient stability under a modest vacuum of 10-8 ~ 10-9 Torr. The present paper is concerned with an extension of our study on the characteristics of the temperature field emitters.

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