A Study of High Intensity Focusing Ultrasonic Transducer

High intensity focused ultrasound (HIFU) is the fourth brand-new and efficient means to cure tumour acknowledged by the medical field. Study of ultrasonic transducer is a core part of HIFU technique, In order to ensure reliability and safety of treatment, it is a key for HIFU technique to realize accurate focusing of ultrasonic energy. In the thesis, ultrasonic focusing method, studies of current situations of cell and multiplex array focusing transducers and their existing problems are illustrated based on analyzing challenges faced by HIFU treatment at present. This study suggested that phased array was theoretically easy for realizing accurate control of computer， however, unbeneficial factors and engineering technical problems still exist; How to promote intensity of the focal spot of cell array focusing transducer, enlarge scope of the focal area and improve control way of the focal spot was a bottleneck problem for publicizing and applying cell array focusing transducer and one of urgent research topics for ensuring curative effect of HIFU and avoiding heat damages.

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High-intensity focused ultrasound-induced mechanochemical transduction in synthetic elastomers

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1901047116 ◽

2019 ◽

Vol 116 (21) ◽

pp. 10214-10222 ◽

Cited By ~ 9

Author(s):

Gun Kim ◽

Vivian M. Lau ◽

Abigail J. Halmes ◽

Michael L. Oelze ◽

Jeffrey S. Moore ◽

...

Keyword(s):

High Intensity ◽

Cellular Response ◽

Focused Ultrasound ◽

Focal Spot ◽

Color Change ◽

Uv Light ◽

High Intensity Focused Ultrasound ◽

Photon Flux ◽

Mechanical Stimuli ◽

Mechanochemical Transduction

While study in the field of polymer mechanochemistry has yielded mechanophores that perform various chemical reactions in response to mechanical stimuli, there is not yet a triggering method compatible with biological systems. Applications such as using mechanoluminescence to generate localized photon flux in vivo for optogenetics would greatly benefit from such an approach. Here we introduce a method of triggering mechanophores by using high-intensity focused ultrasound (HIFU) as a remote energy source to drive the spatially and temporally resolved mechanical-to-chemical transduction of mechanoresponsive polymers. A HIFU setup capable of controlling the excitation pressure, spatial location, and duration of exposure is employed to activate mechanochemical reactions in a cross-linked elastomeric polymer in a noninvasive fashion. One reaction is the chromogenic isomerization of a naphthopyran mechanophore embedded in a polydimethylsiloxane (PDMS) network. Under HIFU irradiation evidence of the mechanochemical transduction is the observation of a reversible color change as expected for the isomerization. The elastomer exhibits this distinguishable color change at the focal spot, depending on ultrasonic exposure conditions. A second reaction is the demonstration that HIFU irradiation successfully triggers a luminescent dioxetane, resulting in localized generation of visible blue light at the focal spot. In contrast to conventional stimuli such as UV light, heat, and uniaxial compression/tension testing, HIFU irradiation provides spatiotemporal control of the mechanochemical activation through targeted but noninvasive ultrasonic energy deposition. Targeted, remote light generation is potentially useful in biomedical applications such as optogenetics where a light source is used to trigger a cellular response.

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Ultrasound Acoustic Radiation Force Impulse imaging for High Intensity Focused Ultrasound focal spot localization

2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) ◽

10.1109/embc.2018.8513591 ◽

2018 ◽

Author(s):

A. Cafarelli ◽

L.A. Chanel ◽

F. Di Bartolo ◽

H. Locteau ◽

S. Tognarelli ◽

...

Keyword(s):

High Intensity ◽

Focused Ultrasound ◽

Focal Spot ◽

Acoustic Radiation ◽

Radiation Force ◽

Acoustic Radiation Force ◽

High Intensity Focused Ultrasound ◽

Acoustic Radiation Force Impulse

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A Study of Temperature Measurement Technique of High Intensity Focusing Ultrasonic Therapy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.201-202.521 ◽

2012 ◽

Vol 201-202 ◽

pp. 521-524

Author(s):

Li Liu ◽

Jian Sun

Keyword(s):

Temperature Measurement ◽

Measurement Technique ◽

High Intensity ◽

Focused Ultrasound ◽

The Body ◽

High Intensity Focused Ultrasound ◽

Ultrasonic Therapy ◽

Normal Tissues ◽

Existing Problems ◽

Temperature Measurement Technique

High intensity focused ultrasound (HIFU) is the fourth brand-new and efficient means to cure tumour acknowledged by the medical field. China is one of countries applying HIFU to clinical oncotherapy earliest in the world. However, a considerable part of HIFU equipments which have been put on the market leave unused because accidental injuries such as ambustion to the body surface, tumour tissue residues in the target section or damages to normal tissues are often caused in HIFU clinical treatment. In the thesis, temperature measurement technique of high-intensity focusing ultrasonic therapy is introduced; features and existing problems of two methods (ultrasound and MRI) which are usually used at home and abroad to guide and monitor HIFU treatment are focally analyzed and illustrated.

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