Photo acoustic drug delivery is a technique for localized drug delivery by laser-induced hydrodynamic pressure following cavitation bubble expansion and collapse. Photoacoustic drug delivery was investigated on gelatin-based thrombus models with planar and cylindrical geometries by use of one microsecond laser pulses. Solutions of a hydrophobic dye in mineral oil permitted monitoring of deliver...

The paper describes some experintental investigations of the formation and collapse of cavitation bubbles. The experiments were carried on in the high-speed water tunnel of the Hydrodynantics Laboratory of the California Institute of Technology under the sponsorship of the Research and Development Division of the Bureau of Ordnan ce of the U. S. Navy and the Fluid Mechanics Section of the Offic...

an adjuvant to antimicrobial therapy, targeted at both planktonic and biofilm (sessile) organisms. Our previous work showed that ultrasound (US) effectively enhances the bactericidal activity of certain antibiotics against planktonic cultures (Pitt et al., 1994; Rediske et al., 1999) and in vitro biofilms (Johnson et al., 1998; Qian et al., 1999) and in vivo biofilms (Carmen et al., 2004b, 2005...

Seattle, Washington 98105 [email protected] In order to better understand the contribution of bubble collapse to stone comminution in shockwave lithotripsy, the shockinduced and Rayleigh collapse of a spherical air bubble is investigated using numerical simulations, and the free-field collapse of a cavitation bubble is studied experimentally. In shock-induced collapse near a wall, it is...

Several recent experimental and allalytical investigations of cavitating flows have revealed new phenomena which clearly affect how we should view cavitation growth arid collapse and the strategies used t o ameliorate its adverse effects. On the scale of individual bubbles it is now clear that the dynamics and acoustics of single bubbles are severely affected by the distortion of the bubble by ...

Calculations of the collapse dynamics of a cloud of cavitation bubbles confirm the speculakions of M#rch and his co-workers and demonstrate that collapse occurs as a result of the inward propagation of a shock wave which grows rapidly in magnitude. Results are presented showing the evolving dynamics of the cloud and the resulting far-field acoustic noise.

In many cavitating liquid flows, when the number and concentration of the bubbles exceeds some critical level, the flow becomes unsteady and large clouds of cavitating bubbles are periodically formed and then collapse when convected into regions of higher pressure. This phenomenon is known as cloud cavitation and when it occurs it is almost always associated with a substantial increase in the c...

In many cavitating liquid flows, when the number and concentration of the bubbles exceeds some critical level, the flow becomes unsteady and large clouds of cavitating bubbles are periodically formed and then collapse when convected into regions of higher pressure. This phenomenon is known as cloud cavitation and when it occurs it is almost always associated with a substantial increase in the c...

1. Introduction Together with the chemical effects of ultrasound, light is often emitted [1-5]. Such sonoluminescence provides an extremely useful spectroscopic probe of the conditions created during cavitation bubble collapse. Acoustic cavitation is the origin of both sonochemistry and sonoluminescence. The collapse of bubbles caused by cavitation produces intense local heating and high pressu...

Sonoporation is the membrane disruption generated by ultrasound and has been exploited as a non-viral strategy for drug and gene delivery. Acoustic cavitation of microbubbles has been recognized to play an important role in sonoporation. However, due to the lack of adequate techniques for precise control of cavitation activities and real-time assessment of the resulting sub-micron process of so...