The effects of phase modulated excitation on the focused acoustic field.

07:00 EST 28th November 2019 | BioPortfolio

Summary of "The effects of phase modulated excitation on the focused acoustic field."

Various modulation approaches, such as amplitude and frequency modulation, have been applied widely to modify the acoustic field and improve the performance of ultrasound imaging and therapy. However, phase modulation has not been investigated extensively in the ultrasound applications, especially at long pulse duration. In this study, the effects of phase modulation on the acoustic field were investigated. The radiated acoustic pressure waveforms produced using different phase modulation strategies (i.e., sequential phase inversion every cycle, every two cycles, and random phase inversion) were explored, and the distributions of acoustic pressure and average acoustic intensity along and transverse to the transducer axis were compared with those of a sinusoidal wave excitation in both measurement and simulation. It is found that the phase inversion between the modulated signals is not clearly seen in the radiated waveform because of the limited fractional bandwidth of the therapeutic ultrasound transducer. As a result, the radiated waveform has a higher oscillating frequency, and the pressure at the focus and -6 dB beam size are decreased. Both simulation and measurement show similar trends. Furthermore, produced acoustic fields of the phased array using these phase modulation strategies were also simulated at the varied lateral and axial focus shifting distances. The magnitude and beam size of both the main lobe and grating lobe are found between them, especially at the large focus shifting. In summary, the acoustic field is dependent on the phase modulation and the appropriate excitation scheme could improve the ultrasound application.


Journal Details

This article was published in the following journal.

Name: IEEE transactions on ultrasonics, ferroelectrics, and frequency control
ISSN: 1525-8955


DeepDyve research library

PubMed Articles [25971 Associated PubMed Articles listed on BioPortfolio]

Dynamical diffraction effects on the geometric phase of inhomogeneous strain fields.

In specimens with an inhomogeneous displacement field in electron beam direction dynamical diffraction effects lead to complex non-linear properties of the diffracted electron wave. Consequently, the ...

Novel Acoustic Coupling Bath using Magnetite Nanoparticles for MR-Guided Transcranial Focused Ultrasound Surgery.

Acoustic coupling baths, nominally composed of degassed water, play important roles during transcranial focused ultrasound surgery. However, this large water bolus also degrades the quality of intraop...

Coherent control of acoustic phonons by seeded Brillouin scattering in polarization-maintaining fibers.

Coherent excitation of phonons by optical waves, one of the most important channels for light-matter interactions, provides a promising route for optical manipulation of microscopic acoustic phonons f...

Heating of Polymer Films Induced by High-Intensity Focused Ultrasound: Study of Acoustic and Thermal Effects.

This paper presents the study of the thermal and acoustic effects occurring in polymer samples of different thicknesses receiving high-intensity focused ultrasound (HIFU). Whereas the heating mechanis...

Evaluation of magnetic resonance imaging acoustic noise reduction technology by magnetic gradient waveform control.

ComforTone is a noise reduction technology used in magnetic resonance imaging (MRI) systems; it suppresses acoustic noise by modifying pulse sequences, which appropriately changes the magnetic field g...

Clinical Trials [8127 Associated Clinical Trials listed on BioPortfolio]

Acoustic Neuromodulation (ANM) for Youth With Anxiety Disorders

The acoustic neuromodulation trial (ANM-T) is a two-phase, single-site, pilot randomized clinical trial examining the feasibility of completing a larger scale efficacy study of a novel tre...

The Effects of Transcranial Focused Ultrasound on Human Motor Learning

Transcranial focused ultrasound (tFUS) is a form of neuromodulation that uses a single element transducer to produce highly focused low-intensity acoustic energy that can be used to affect...

Degree of Benefit From Low-Frequency Acoustic Amplification Using the Advanced Bionics Acoustic Earhook

The primary objective of this study is to obtain a greater understanding of the range in benefit from acoustic amplification combined with electric stimulation in cochlear implant recipien...

Effects of Transcranial Focused Ultrasound on Human Primary Motor Cortex Using 7T fMRI

Transcranial focused ultrasound (tFUS) is a form of neuromodulation that uses a single element transducer to produce highly focused low-intensity acoustic energy that can be used to affect...

Music-based Intervention for the Reduction of Pain

This study aims to compare the impact of listening to frequency-modulated music vs. non-modulated music (both researcher-selected), and to test whether there are differential effects on pa...

Medical and Biotech [MESH] Definitions

A loosely defined group of drugs that tend to increase behavioral alertness, agitation, or excitation. They work by a variety of mechanisms, but usually not by direct excitation of neurons. The many drugs that have such actions as side effects to their main therapeutic use are not included here.

Separation of molecules and particles by a simultaneous action of carrier liquid flow and focusing field forces (electrical, sedimentation, or thermal), without a stationary phase.

CONFORMAL RADIOTHERAPY that combines several intensity-modulated beams to provide improved dose homogeneity and highly conformal dose distributions.

Tricyclic antidepressant similar in action and side effects to IMIPRAMINE. It may produce excitation.

The interval between two successive CELL DIVISIONS during which the CHROMOSOMES are not individually distinguishable. It is composed of the G phases (G1 PHASE; G0 PHASE; G2 PHASE) and S PHASE (when DNA replication occurs).

Quick Search

DeepDyve research library

Relevant Topics

Radiology is the branch of medicine that studies imaging of the body; X-ray (basic, angiography, barium swallows), ultrasound, MRI, CT and PET. These imaging techniques can be used to diagnose, but also to treat a range of conditions, by allowing visuali...

A diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease. For example: to diagnose diseases to measure the progress or recovery from disease to confirm that a person is free from disease Clin...

Searches Linking to this Article