Wideband Multimode Excitation by a Double-Parabolic-Reflector Ultrasonic Transducer

Chen, Kang; Irie, Takasuke; Iijima, Takashi; Morita, Takeshi

doi:10.1109/tuffc.2020.2978234

Cited by 9 publications

(11 citation statements)

References 28 publications

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“…We had studied DPLUS with ~40 mm long thin waveguide (made of duralumin A2017) in order for understanding the working principle and exploring the excitable vibration amplitude in the thin waveguide [15][16][17]. Results showed that ~7 m/s of vibration velocity amplitude could be realized in the thin waveguide and acoustic pressure in water of over 7 MPa (spatial peak temporal average intensity of ~1.6 kW cm $ ⁄ ) between 1 to 2 MHz could be estimated under the resonant excitation of the thin waveguide [15], thus indicating the highpower performance of DPLUS.…”

Section: A Dplus With a Long Fused Quartz Thin Waveguidementioning

confidence: 99%

Low-Loss Ultrasound Transmission Through Waveguide From Double Parabolic Reflectors (DPLUS) for Thermal Ablation

Chen

Irie²,

Iijima

et al. 2022

IEEE Access

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In this paper, to advance acoustic waveguide transducers towards practical thermal ablation applications, we studied DPLUS (double parabolic reflectors wave-guided ultrasonic transducer) with a 1-m long (0.6-mm radius) and low-loss fused quartz thin waveguide working at the optimal frequency of 2.2 MHz, and the thermal effects to the tissue under different ultrasound exposure time. The measured vibration attenuation coefficient of the fused quartz thin waveguide is ~0.0123 dB/MHz/cm, and such low-loss characteristic is one of the keys of the studied DPLUS for realizing thermal ablation. Under the transmitted axial vibration velocity amplitude 𝑣 !"# at the thin waveguide tip of 1 m/s and the ultrasound exposure time of 1 s, 5 s, 10 s, 20 s, the measured temperature rises in the chicken breast tissue showed good agreements with the simulation results. Lesions were observed in the tissue under the exposure of 10 s, 20 s, and 30 s. The lesion size increases with the exposure time but the measured axial and lateral widths of the lesions were smaller than 2 mm. The presented results in this paper showed that for the first time thermal ablation was achieved by a long thin-waveguide DPLUS which becomes an important progress of DPLUS towards practical MIT applications.

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Section: A Dplus With a Long Fused Quartz Thin Waveguidementioning

confidence: 99%

Low-Loss Ultrasound Transmission Through Waveguide From Double Parabolic Reflectors (DPLUS) for Thermal Ablation

Chen

Irie²,

Iijima

et al. 2022

IEEE Access

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“…However, a BLT has only a single working frequency lower than several hundred kilohertz, which limits the application possibilities. Recently, Chen et al studied a double-parabolic-reflector ultrasonic transducer (DPLUS) [4][5][6][7], which consists of a lead zirconate titanate (PZT) ring, double-parabolic reflectors (1st and 2nd reflectors), which share the same focal point, and a thin waveguide. The 1st reflector focuses the incident plane wave from the PZT ring, and the 2nd reflector reflects the ultrasound and turns it into an in-phase plane wave, which propagates into the thin waveguide.…”

Section: Introductionmentioning

confidence: 99%

Tube-type double-parabolic-reflector ultrasonic transducer (T-DPLUS)

Yamada

Chen

Irie³

et al. 2022

Acoust. Sci. & Tech.

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“…10) However, only one or two working frequencies can be used for such a transducer which cannot be used to examine the frequency dependence of various applications. 16) The frequency dependence is essential for revealing the optimal working frequency for applications. As for high-frequency high-power ultrasound, around 10 kW cm −2 of spatial peak temporal average intensity is the threshold for mechanical HIFU treatment.…”

Section: Introductionmentioning

confidence: 99%

“…At the vibration condition without the load of water, DPLUS should realize at least peak vibration velocity of 5.8 m s −1 . Since DPLUS can excite over 20 harmonic longitudinal modes from the thin waveguide in the range of 20 kHz-2.5 MHz, 16) for example, in the case of a 40 mm long thin waveguide which is used in this study, these harmonic resonant frequencies should be ń f , 1 where f 1 equals 31 kHz and n is an odd number, then our target for DPLUS is to realize at least 5.8 m s −1 for each resonant mode.…”

Section: Introductionmentioning

confidence: 99%

Selection criteria of piezoelectric materials for double-parabolic-reflectors ultrasonic transducers (DPLUS) for high-power ultrasound

Chen

Irie²,

Iijima

et al. 2021

Jpn. J. Appl. Phys.

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To suit double parabolic reflectors wave-guided ultrasonic transducer (DPLUS) for high-power ultrasound applications, we investigated the selection criteria of piezoelectric materials for DPLUS. Four piezoelectric materials were prepared: two lead–zirconate–titanate (PZT) types and two lead-free types. For non-resonant excitation of the DPLUS waveguide, the piezoelectric constant e and the thickness of piezoelectric materials are two important evaluation indexes. PZT 5H was found as the best candidate. For resonant excitation of the DPLUS waveguide, two situations should be distinguished. For low-frequency modes excitation, the discussed modes matching issue is essential. For high-frequency modes excitation, high-power properties of the piezoelectric material are important for improving the vibration output of DPLUS; LFP 0202 was found as the best candidate. Low-frequency modes can achieve 8 m s−1 of maximum peak vibration velocity, but high-frequency modes were smaller than 2 m s−1. Results are important to design the DPLUS for various high-power ultrasound applications.

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Wideband Multimode Excitation by a Double-Parabolic-Reflector Ultrasonic Transducer

Cited by 9 publications

References 28 publications

Low-Loss Ultrasound Transmission Through Waveguide From Double Parabolic Reflectors (DPLUS) for Thermal Ablation

Low-Loss Ultrasound Transmission Through Waveguide From Double Parabolic Reflectors (DPLUS) for Thermal Ablation

Tube-type double-parabolic-reflector ultrasonic transducer (T-DPLUS)

Selection criteria of piezoelectric materials for double-parabolic-reflectors ultrasonic transducers (DPLUS) for high-power ultrasound

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