Mechanisms of microbubble-vessel interactions and induced stresses: a numerical study
N Hosseinkhah1, H Chen, T J Matula
1Department of Medical Biophysics, University of Toronto, Sunnybrook Research Institute, 2075 Bayview Avenue, Room C713, Toronto, Ontario M4N 3M5, Canada. nazanin@sri.utoronto.ca
The Journal of the Acoustical Society of America
|August 24, 2013
Summary
Microbubble oscillations in blood vessels can cause damage. This study used numerical simulations to show that vascular invagination, not just bubble jetting, is a key mechanism for this damage.
Area of Science:
- Biomedical Engineering
- Fluid Dynamics
- Computational Mechanics
Background:
- Oscillating microbubbles in microvessels can cause bioeffects and vascular damage.
- Previous research attributed damage to vessel expansion or bubble jetting.
- Recent ultra-high-speed imaging suggests vascular invagination as a potential cause.
Purpose of the Study:
- To investigate the mechanisms of microbubble-induced vascular damage using numerical simulations.
- To incorporate viscoelastic properties of microvessels for a more realistic model.
- To quantify vascular stresses during bubble-vessel interactions.
Main Methods:
- Developed and validated a finite element model of a coupled bubble/fluid/vessel system.
- Incorporated viscoelastic properties of microvessels into the numerical model.
- Calculated wall shear stress (WSS) and circumferential stress (CS) from simulations.
Main Results:
- Simulated oscillation amplitudes were within 15% of experimental measurements.
- Maximum WSS ranged from 1.1-18.3 kPa during expansion and 1.5-74 kPa during collapse.
- Circumferential stress ranged from 0.43-2.2 MPa during expansion and 0.44-6 MPa during invagination.
Conclusions:
- Vascular damage can occur during microbubble-induced vascular invaginations.
- The study identified thresholds where stresses are higher during vessel invagination.
- Numerical simulations provide crucial insights into microbubble-vascular interactions and damage mechanisms.
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