Material properties from acoustic radiation force step response

AUTOR(ES)

Orescanin, Marko

FONTE

Acoustical Society of America

RESUMO

An ultrasonic technique for estimating viscoelastic properties of hydrogels, including engineered biological tissues, is being developed. An acoustic radiation force is applied to deform the gel locally while Doppler pulses track the induced movement. The system efficiently couples radiation force to the medium through an embedded scattering sphere. A single-element, spherically-focused, circular piston element transmits a continuous-wave burst to suddenly apply and remove a radiation force to the sphere. Simultaneously, a linear array and spectral Doppler technique are applied to track the position of the sphere over time. The complex shear modulus of the gel was estimated by applying a harmonic oscillator model to measurements of time-varying sphere displacement. Assuming that the stress-strain response of the surrounding gel is linear, this model yields an impulse response function for the gel system that may be used to estimate material properties for other load functions. The method is designed to explore the force-frequency landscape of cell-matrix viscoelasticity. Reported measurements of the shear modulus of gelatin gels at two concentrations are in close agreement with independent rheometer measurements of the same gels. Accurate modulus measurements require that the rate of Doppler-pulse transmission be matched to a priori estimates of gel properties.

Documentos Relacionados

• Dynamic radiation force of acoustic waves on absorbing spheres
• Elastografia acoustic radiation force impulse dos olhos de cães braquicefálicos
• Elastografia acoustic radiation force impulse (ARFI) de afecções testiculares em cães: resultados iniciais
• Elastografia acoustic radiation force impulse (ARFI) das glândulas adrenais de cães adultos saudáveis
• [Elastografia acoustic radiation force impulse (ARFI) da articulação do joelho de beagles saudáveis]