Physics Department Faculty Search Candidate, "From Imaging to Therapy: The Physics of Gas Bubbles for Medical Applications of Ultrasound," by Dr. Elisabetta Sassaroli, Dept. of Radiology, Brigham & Women's Hospital and Harvard Medical School

Science / Technology - Colloquium

Wednesday, February 21, 2007
4:00 PM-5:00 PM

Gas bubbles powerfully influence the acoustics in tissues and liquids. This presentation gives an introduction to the physics of gas bubbles, focusing primarily on biomedical applications. In a sound field of sufficient amplitude, bubbles oscillate nonlinearly and emit harmonic and subharmonic components of the driving frequency. In practice, microscopic bubbles are injected into the blood stream to increase the echo from blood, in particular at the level of the microcirculation. As the pressure is further increased, bubbles may undergo inertial cavitation. Inertial cavitation is characterized by the sudden expansion and then rapid collapse of the bubble. Bubble collapse can generate shock waves and shear, which can produce erosion and bioeffects. There is clear evidence that the permeability of the cell membrane to large molecules is increased when suspensions of cells are exposed to ultrasound in the presence of microbubbles.

The understanding of bubble acoustical behavior in a confined geometry is essential for their control and exploitation when injected into the blood stream. Experimental and numerical modeling of microbubble behavior in micron-sized tubes and tunnels embedded in gel will be presented

Cost: FREE

Suggested Audiences: College

E-mail: snj@wpi.edu
Phone: 508-949-0782

Last Modified: February 9, 2007 at 1:49 PM