The research in the laboratory for bio-medical fluid
mechanics focuses on flows in artificial organs and implants
like artificial heart valve prostheses, blood pumps, microfluidic
filter systems, etc. and on flows in biological/human systems
such as the circulatory blood system and the human airways.
Experimental methods like scanning and digital particle-image
velocimetry (SPIV, PIV) and numerical schemes are used to
analyze and optimize the flow field through such
configurations.
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CFD determined streamlines through a model of the
human nose during inhalation.
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PIV measured velocity field through a three-leaflet
aortic heart valve prosthesis in pulsatile flow.
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All research activities are performed in close relation with
industrial and clinical partners. Studies are supported by
industrial grants, the German Research Association (DFG),
European Union, and other public institutions.
The investigation of artificial heart valves for certification (ISO,
CFN, FDA) and research comprises, among other things,
standard tests to analyze leakage, cavitation, and leaflet
kinematics in pulsatile flow. The measuring equipment
includes modern digital high-speed cameras, high-intensity
Nd:Yag lasers, and high-resolution CCD cameras to obtain
top quality data for various intricate flows.
For example, PIV measurements are performed for a three-leaflet
heart valve prosthesis in pulsatile flow to understand
qualitatively and quantitatively the flow physics. The results,
that evidence the vortex dynamics, stagnation regions, shear
layers etc. behind the leaflets, serve as a data base to improve
the valve design. High-speed recordings of
the leaflet kinematics provide additional information of the
leaflet motion and the impact velocity, which is important for
possible cavitation at closure and the valve's lifespan.
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Optical setup to conduct for PIV measurements in a
micro-axial blood pump rotating at 33000 rpm.
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PIV measured velocity field in a micro-axial
blood pump rotating at 33000 rpm.
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The flow in a micro-axial blood pump is measured using
phase-locked DPIV at a rotating speed of 33000 rpm. A
picture of the optical setup is given above. The highly
resolved velocity distributions provide information on the onset
of flow separation at critical pressure differences and
represent necessary data to optimize the pump geometry with
respect to blood damage.
In a clinical project an inspection system was built at the
Institute of Aerodynamics to determine the surface
coordinates of the abdominal wall of a human body. The
system is based on the technique of light-grid topometry. The
abdomen wall compliance and flexibility is tested using
parameters calculated from the surface profiles.
Reconstructed surface of the abdominal wall of a lying
patient after deep inhalation at maximum extension.
The system
allows to investigate different materials of synthetic meshes
after being implanted in the abdominal region. Furthermore, it
can be used to diagnose problems of the curvature of the
spine.
Last Update: 17:08:20 - 12.06.2009
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