Coupling of wideband impulses generated by granular chains into liquids
File(s)
Conference
Author(s)
Type
Conference Paper
Abstract
An ultrasonic transducer technology to generate wideband impulses using a
one-dimensional chain of spheres was previously presented. The Hertzian contact
between the spheres causes the nonlinearity of the system to increase, which
transforms high amplitude narrowband sinusoidal input into a train of wideband
impulses. Generation of short duration ultrasonic pulses is desirable both in
diagnostic and therapeutic ultrasound. Nevertheless, the biggest challenge in
terms of adaptation to biomedical ultrasound is the coupling of the ultrasonic
energy into biological tissue.
An analytical model was created to address the coupling issue. Effect of the
matching layer was modelled as a flexible thin plate clamped from the edges.
Model was verified against hydrophone measurements. Different coupling
materials, such as glass, aluminium, acrylic, silicon rubber, and vitreous
carbon, was analysed with this model. Results showed that soft matching layers
such as acrylic and rubber inhibit the generation of higher order harmonics.
Between the hard matching materials, vitreous carbon achieved the best results
due to its acoustic impedance.
one-dimensional chain of spheres was previously presented. The Hertzian contact
between the spheres causes the nonlinearity of the system to increase, which
transforms high amplitude narrowband sinusoidal input into a train of wideband
impulses. Generation of short duration ultrasonic pulses is desirable both in
diagnostic and therapeutic ultrasound. Nevertheless, the biggest challenge in
terms of adaptation to biomedical ultrasound is the coupling of the ultrasonic
energy into biological tissue.
An analytical model was created to address the coupling issue. Effect of the
matching layer was modelled as a flexible thin plate clamped from the edges.
Model was verified against hydrophone measurements. Different coupling
materials, such as glass, aluminium, acrylic, silicon rubber, and vitreous
carbon, was analysed with this model. Results showed that soft matching layers
such as acrylic and rubber inhibit the generation of higher order harmonics.
Between the hard matching materials, vitreous carbon achieved the best results
due to its acoustic impedance.
Date Issued
2019-02-05
Date Acceptance
2019-02-05
Citation
2019
Publisher
IEEE
Identifier
http://arxiv.org/abs/1902.01962v1
Source
International Ultrasonics Symposium
Subjects
physics.med-ph
physics.med-ph
physics.app-ph