Biomechanická problematika tenkostěnných žil mozku

• Main Author: Hemza, Jan
• Other Authors: Maršík, František
• Format: Doctoral Thesis
• Language: Czech
• Published: 2010
• Online Access: http://www.nusl.cz/ntk/nusl-450496

Biomechanical material properties of the bridging brain veins are investigated experimentally (A Nikon light microscope was used for the histo-anatomical study and viskoelastic properties was measured on a MTS 858.2 Mini Bionix system ) and theoretically. The main goal of the developed theory was to formulate the biomechanical conditions (geometrical dimensions, viscoelastic properties of veins and blood fluid flow conditions) at which unstable behavior or even vein collapse can occur. The study of the geometry and topology of bridging veins was carried out by a magnetic resonance (Siemens Magnetom Symphony1,5 T) and a stereomicroscope (Nikon SMZ 1500) complemented with a digital camera (Nikon Coolpix E995) and Lucia Net software. From the biomechanical point of view, experimental findings can be summarized as follows: the existence of two types of venous brain systems; thin and thick wall veins with a one order difference in elastic modulus magnitude high sensitivity of the thin wall veins on the blood flow rate and extension or contraction on their structural stability the existence of continuing small wall vibration under physiological conditions Under small deformations conditions, the shear modulus was shown experimentally to be in the range (2÷4)·10 4 Pa with a Young modulus E= (0.6÷1.2)·10 5...