The study described herein was undertaken to determine the role of proteins, in general, and collagen, in particular, in the observed absorption and speed of ultrasound in biological tissues. It had earlier been observed that ultrasonic absorption in tissues occurs at the macromolecular level, •'z though an additional contribution to attenuation arises from tissue structural features. a Each of...

In this paper procedures for estimating the sound absorption coefficient when the specimen has inherently low absorption are discussed. Examples of this include the measurement of the absorption coefficient of pavements, closed cell foams and other barrier materials whose absorption coefficient is nevertheless required, and the measurement of sound absorption of muffler components such as perfo...

The aim of this paper was twofold: first, to present a virtual instrument for characterization of the cataract severity in the lens of the eye, based on the indirect measurements of ultrasound attenuation coefficient, second, to evaluate the instrument in vitro by assessment of measurement errors in case of the four different phantoms with a priory known characteristics (pure water, castor oil,...

The formation of burn-scar tissue in human skin profoundly alters, among other things, the structure of the dermis. We present a method to characterize dermal scar tissue by the measurement of the near-infrared attenuation coefficient using optical coherence tomography (OCT). To generate accurate en face parametric images of attenuation, we found it critical to first identify (using speckle dec...

Cataract is very frequent disease of human eye and the diagnosis of this disease is not difficult. However, it is important to describe it quantitatively, but it is difficult using only the slit lamp. Ultrasound examinations are widely used in ophthalmology. Piezoelectric crystals generate ultrasound waves of 5–50 MHz. Short pulses of 2 to 3 cycles are sent from transducer into the eye. These p...

BACKGROUND This study describes a series of experimental work completed towards characterizing candidate materials for fabricating brain and muscle tissue mimicking phantoms. METHODS The acoustic speed, attenuation, impedance, thermal diffusivity, specific heat and thermal conductivity were measured. RESULTS The resulting brain (2% w/v agar-1.2% w/v Silica Dioxide-25%v/v evaporated milk) an...

The purpose of this study is to propose and investigate a new approach for discriminating between focal and non-focal hemispheres in intractable temporal lobe epilepsy, based on applying multivariate time series analysis to the discharge-free background brain activity observed in nocturnal electrocorticogram (ECoG) time series. Five unilateral focal patients and one bilateral focal patient were...

In this study, using methacrylic and ascorbic acid in gelatin initiated by copper (MAGIC-f) polymer gel after megavoltage energy exposure, the sensitivity of the ultrasound velocity and attenuation coefficient dose-dependent parameters was evaluated. The MAGIC-f polymer gel was irradiated under 1.25 MeV cobalt-60, ranging from 0 to 60 Gy in 2-Gy steps, and received dose uniformity and accuracy ...

Although loss of muscle mass is considered a cause of diminished muscle strength with aging, little is known regarding whether composition of aging muscle affects strength. The skeletal muscle attenuation coefficient, as determined by computed tomography, is a noninvasive measure of muscle density, and lower values reflect increased muscle lipid content. This investigation examined the hypothes...