A Study of Cavitation Activity in Ex vivo Tissue Exposed to High Intensity Focused Ultrasound

Author(s):  
James McLaughlan ◽  
Ian Rivens ◽  
Gail ter Haar
2010 ◽  
Vol 36 (8) ◽  
pp. 1327-1344 ◽  
Author(s):  
James McLaughlan ◽  
Ian Rivens ◽  
Timothy Leighton ◽  
Gail ter Haar

Author(s):  
Yufeng Zhou ◽  
Bryan W. Cunitz ◽  
Barbrina Dunmire ◽  
Yak‐Nam Wang ◽  
Steven G. Karl ◽  
...  

Author(s):  
David Sanford ◽  
Christoph Schaal

Abstract High-intensity focused ultrasound (HIFU) is used clinically to heat cells therapeutically or to destroy them through heat or cavitation. In homogeneous media, the highest wave amplitudes occur at a predictable focal region. However, HIFU is generally not used in the proximity of bones due to wave absorption and scattering. Ultrasound is passed through the skull in some clinical trials, but the complex geometry of the spine poses a greater targeting challenge and currently prohibits therapeutic ultrasound treatments near the vertebral column. This paper presents a comprehensive experimental study involving shadowgraphy and hydrophone measurements to determine the spatial distribution of pressure amplitudes from induced HIFU waves near vertebrae. First, a bone-like composite plate that is partially obstructing the induced waves is shown to break the conical HIFU form into two regions. Wave images are captured using pulsed laser shadowgraphy, and hydrophone measurements over the same region are compared to the shadowgraphy intensity plots to validate the procedure. Next, shadowgraphy is performed for an individual, clean, ex-vivo feline vertebra. The results indicate that shadowgraphy can be used to determine energy deposition patterns and to determine heating at a specific location. The latter is confirmed through additional temperature measurements. Overall, these laboratory experiments may help determine the efficacy of warming specific nerve cells within mammal vertebrae without causing damage to adjacent tissue.


2019 ◽  
Vol 5 (1) ◽  
pp. 585-588
Author(s):  
Benedikt George ◽  
Michael Fink ◽  
Helmut Ermert ◽  
Stefan J. Rupitsch ◽  
Pia T. Hiltl ◽  
...  

AbstractAn approach to improve chemotherapy, while minimizing side effects, is a local drug release close to the tumorous tissue. For this purpose, the active drug component is often bound to nanoparticles employed as drug carriers. In the present study, we investigate sonosensitive, biocompatible poly-(L)-lactic acid (PLA) nanoparticles, which shall be used as drug carriers. For drug release, High Intensity Focused Ultrasound (HIFU) will be employed to introduce inertial cavitation, which separates the active drug component from the drug carrier. The cavitation effect generates an acoustic noise signal, which characterizes the cavitation activity and is expected to serve simultaneously as an indicator for the release of the active drug component. Depending on the ultrasound frequency, different acoustic levels of the inertial cavitation activity were measured. Investigations using a setup for passive cavitation detection (PCD) deliver quantitative results regarding the frequency dependence of the cavitation activity level of nanoparticles and reference media.


2018 ◽  
Vol 144 (3) ◽  
pp. 1824-1824 ◽  
Author(s):  
Christopher Bawiec ◽  
Christopher Hunter ◽  
Wayne Kreider ◽  
Adam D. Maxwell ◽  
Vera A. Khokhlova ◽  
...  

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