Generation of High-Intensity Focused Ultrasound by Carbon Nanotube Opto-Acoustic Lens

2014 ◽  
Vol 81 (8) ◽  
Author(s):  
L. H. Tong ◽  
C. W. Lim ◽  
Y. C. Li
Keyword(s):  
High Intensity ◽  
Focused Ultrasound ◽  
Focal Point ◽  
Pulsed Laser ◽  
High Intensity Focused Ultrasound ◽  
Acoustic Performance ◽  
Concave Lens ◽  
New Guidelines ◽  
Opening Up ◽  
Good Agreement

A new model of high-intensity focused ultrasound generation by radiation from a composite nanothinfilm made of carbon nanotubes (CNTs) and elastomeric polymer is presented in this paper. The composite nanothinfilm is deposited to the surface of a concave lens and the performance of focused ultrasound generated by an incident pulsed laser onto the lens is analyzed. The analysis and results are verified by comparing with published experimental data and very good agreement is recorded. The opto-acoustic pressure on the symmetric axis and the lateral focal plane are investigated analytically and the result indicates that excellent acoustic performance is found to be present in the vicinity of the focus region. The temporal performance of the focused lens is also investigated both at the focal point and the prefocal zone and very good agreement comparing with experiment is obtained. Conclusively, it is demonstrated theoretically that there exists an optimal input frequency for a pulsed laser at which the performance of the focused lens can be tremendously enhanced. In general, this new analytical model provides new guidelines in the design of high-intensity ultrasound lens, hence opening up promising applications to medical ultrasonography treatment.

High-Intensity Focused Ultrasound Scattering at Mammal Vertebrae

2020 ◽  
Author(s):  
David Sanford ◽  
Christoph Schaal
Keyword(s):  
High Intensity ◽  
Laboratory Experiments ◽  
Energy Deposition ◽  
Focused Ultrasound ◽  
Complex Geometry ◽  
Ex Vivo ◽  
Pulsed Laser ◽  
High Intensity Focused Ultrasound ◽  
Focal Region ◽  
Homogeneous Media

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.

High intensity focused ultrasound with large aperture transducers: A MRI based focal point correction for tissue heterogeneity

2012 ◽  
Vol 39 (4) ◽  
pp. 1936-1945 ◽  
Author(s):  
Charles Mougenot ◽  
Matti Tillander ◽  
Julius Koskela ◽  
Max O. Köhler ◽  
Chrit Moonen ◽  
...  
Keyword(s):  
High Intensity ◽  
Focused Ultrasound ◽  
Focal Point ◽  
High Intensity Focused Ultrasound ◽  
Tissue Heterogeneity ◽  
Large Aperture

A nanoparticle enabled focused ultrasound-stimulated magnetic resonance imaging spotlight

2019 ◽  
Vol 55 (69) ◽  
pp. 10261-10264 ◽  
Author(s):  
Tian Deng ◽  
Le Zhang ◽  
Holden H. Wu ◽  
Jeffrey I. Zink
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Intensity ◽  
Focused Ultrasound ◽  
Focal Point ◽  
Region Of Interest ◽  
High Intensity Focused Ultrasound ◽  
Resonance Imaging ◽  
Ultrasound Modulation

Periodic high-intensity focused ultrasound modulation of a nanoparticle generates reversible MRI T1 relaxivity changes at the 1.5 mm3 focal point. A modulation enhancement map spotlights the region of interest by increasing contrast almost 100-fold.

260: High Intensity Focused Ultrasound Combined with Endocrine Therapy in Treating High or Intermediate Risk Prostate Cancer

2006 ◽  
Vol 175 (4S) ◽  
pp. 86-86
Author(s):  
Makoto Sumitomo ◽  
Junichi Asakuma ◽  
Yasumasa Hanawa ◽  
Kazuhiko Nagakura ◽  
Masamichi Hayakawa
Keyword(s):  
Prostate Cancer ◽  
Endocrine Therapy ◽  
High Intensity ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
Intermediate Risk ◽  
Risk Prostate Cancer

1400: Early Clinical Experience Using High-Intensity Focused Ultrasound for the Treatment of Renal Tumours

2005 ◽  
Vol 173 (4S) ◽  
pp. 379-380
Author(s):  
James E. Kennedy ◽  
Rowland O. Illing ◽  
Feng Wu ◽  
Gail R. ter Haar ◽  
Rachel R. Phillips ◽  
...  
Keyword(s):  
Clinical Experience ◽  
High Intensity ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
Early Clinical Experience ◽  
Renal Tumours

Das Prostatakarzinom: aktuelle Diagnostik und Therapiestandard

Praxis ◽  
2016 ◽  
Vol 105 (16) ◽  
pp. 971-977
Author(s):  
Jan Brachlow ◽  
Martin Kälin ◽  
Marco Randazzo ◽  
Beat Förster ◽  
Hubert John
Keyword(s):  
High Intensity ◽  
Focused Ultrasound ◽  
High Intensity Focused Ultrasound ◽  
Psa Test ◽  
Eine Hohe ◽  
Psa Screening ◽  
Sekundäre Hormontherapie

Zusammenfassung. Das Prostatakarzinom zeigt eine hohe Prävalenz und ist daher für die behandelnden Ärzte medizinisch, aber auch gesundheitspolitisch relevant. PSA-Screening senkt die karzinomspezifische Mortalität, ist jedoch aufgrund der hohen Prävalenz mit einer Überdiagnostik verbunden. Dies fordert im Gegenzug einen verantwortungsbewussten Umgang mit dem PSA-Test («smarter screening»). Durch die robotergestützte Prostatektomie steht eine Therapie mit geringer Morbidität zur Behandlung des lokalisierten Prostatakarzinoms zur Verfügung. Das fokale Behandlungskonzept der HIFU (high-intensity focused ultrasound) ist vielversprechend, jedoch noch klinisch experimentell und sollte im Rahmen von Studien angeboten werden. Die Behandlungsmöglichkeiten beim metastasierten Prostatakarzinom wurden entscheidend vervielfältigt. Chemotherapie und die sekundäre Hormontherapie werden voraussichtlich vermehrt in früheren Phasen der Krankheit eine Rolle spielen, wodurch die Therapie für den einzelnen Patienten immer komplexer wird und individuell angepasst werden muss.

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