Bioacoustics Research Lab
University of Illinois at Urbana-Champaign | Department of Electrical and Computer Engineering | Department of Bioengineering
Department of Statistics | Coordinated Science Laboratory | Beckman Institute | Food Science and Human Nutrition | Division of Nutritional Sciences | College of Engineering
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William D. O'Brien, Jr. publications:

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Title Attenuation and speed of 10 MHz ultrasound in canine blood of various packed-cell volumes at 37 degrees C.
Author Hughes DJ, Geddes LA, Babbs CF, Bourland JD, Newhouse VL.
Journal Med Biol Eng Comput
Volume
Year 1979
Abstract The attenuation coefficient and the speed of 10 MHz ultrasound were determined in canine blood at 37 degrees C by a differential path-length technique. Blood specimens with packed-cell volumes (p.c.v.) ranging from 0 to 53% were prepared by separating the cells from the plasma and mixing the two components. The mean attenuation coefficient increased linearly with packed-cell volume, the least squares regression function being alpha=0.992 + 0.039 PCV with a standard error of the estimate = 0.255. The speed of 10 MHz ultrasound c in millimetres per second, increased with packed-cell volume, the regression function for a wave equation model being 1/c2 = 0.418 + 2.09x10(exp)(-4) (PCV) - 1.75x10(exp)(-5) (PCV)2 with a standard error of the estimate = 0.0049 (mm/s)(exp)(-2). Both the attention coefficient and speed of 10 MHz ultrasound were greater in blood than in plasma to a degree dependent on the packed-cell volume.


Title Attenuation and speed of ultrasound in lung.
Author Dunn F.
Journal J Acoust Soc Am
Volume
Year 1974
Abstract The frequency dependent of the ultrasonic propagation properties of canine lung inflated to a density of 0.4 g/cm(3) are reported. The attenuation increases exponentially with frequency, and the speed of propagation increases linearly with frequency.


Title Attenuation and speed of ultrasound in lung: Dependence upon frequency and inflation.
Author Dunn F.
Journal J Acoust Soc Am
Volume
Year 1986
Abstract The dependence of the speed of sound and the attenuation coefficient upon exposure frequency, in the range of 1-5 MHz, and upon level of inflation, in the range of mass density 0.35-0.7 g/cm3, are reported. The speed of sound decreases linearly and the attenuation coefficient increases exponentially, for all levels of inflation studied.


Title Attenuation compensation of ultrasonic wave in soft tissue for acoustic impedance measurement of in vivo bone by transducer vibration method.
Author Yoshizawa M, Nakamura Y, Ishiguro M, Moriya T.
Journal Jpn J Appl Phys
Volume
Year 2007
Abstract In this paper, we describe a method of compensating the attenuation of the ultrasound caused by soft tissue in the transducer vibration method for the measurement of the acoustic impedance of in vivo bone. In the in vivo measurement, the acoustic impedance of bone is measured through soft tissue; therefore, the amplitude of the ultrasound reflected from the bone is attenuated. This attenuation causes an error of the order of -20 to -30% when the acoustic impedance is determined from the measured signals. To compensate the attenuation, the attenuation coefficient and length of the soft tissue are measured by the transducer vibration method. In the experiment using a phantom, this method allows the measurement of the acoustic impedance typically with an error as small as -8 to 10%.


Title Attenuation measurements of ultrasound in a kaolin-water slurry: A linear dependence upon frequency.
Author Greenwood MS, Mai JL, Good MS.
Journal J Acoust Soc Am
Volume
Year 1993
Abstract The attenuation of ultrasound through kaolin-water slurry was measured for frequencies ranging from 0.5 to 3.0 MHz. The maximum concentration of the slurry was for a weight percentage of 44% (or a volume fraction of 0.24). The goal of these measurements was to assess the feasibility of using ultrasonic attenuation to determine the concentration of slurry of known composition. The measurements were obtained by consecutively adding kaolin to the slurry and measuring the attenuation at each concentration. After reaching a maximum concentration a dilution technique was used, in which an amount of slurry was remove and water was added, to obtain the attenuation as a function of the concentration. The dilution technique was the more effective method to obtain calibration data. These measurements were carried out using two transducers, having a center frequency of 2.25 MHz, separated by 0.1016m (4.0 in.). The maximum attenuation measured in these experiments was about 100 Np/m, but the experimental apparatus has the capability of measuring a larger attenuation if the distance between the two transducers is decreased. For a given frequency, the data show that 1n V/V(0) depends linearly upon the volume fraction (V is the received voltage for the slurry and V(0) is that obtained for water). This indicated that each particle acts independently in attenuating ultrasound. The data showed that the attenuation is proportional to the frequency and to the volume fraction. The results demonstrated the feasibility of using attenuation measurements to determine slurry concentration. Several theoretical models are discussed that describe the attenuation of ultrasound. The data obtained by several other researchers also show a linear dependence of attenuation upon frequency.


Title Attenuation of coefficient and propagation speed estimates of rat and pig intercostal tissue as a function of temperature.
Author Towa RT, Miller RJ, Frizzell LA, Zachary JF, O'Brien WD Jr.
Journal IEEE Trans UFFC
Volume
Year 2002
Abstract Attenuation coefficient and propagation speed of intercostal tissues were estimated as functions of temperature (22, 30, and 37/spl deg/C) from fresh chest walls from eight 10- to 11-week-old female Sprague-Dawley (SD) rats, eight 21to 24-week-old female Long-Evans (LE) rats, and ten 6- to 10-week-old mixed sex Yorkshire (York) pigs. The primary purpose of the study was to estimate the temperature dependence of the intercostal tissue's attenuation coefficient so that accurate estimates of the in situ (at the pleural surface) acoustic pressure levels could be made for our ultrasound-induced lung hemorrhage studies. The attenuation coefficient of intercostal tissue for both species was independent of the temperature at the discrete frequencies of 3.1 MHz (-0.0076, 0.0065, and 0.016 dB/cm//spl deg/C for SD rats, LE rats, and York pigs, respectively) and 6.2 MHz (-0.015, 0.014, and 0.014 dB/cm//spl deg/C for SD rats, LE rats, and York pigs, respectively). However, the temperature-dependent regressions yielded a significant temperature dependency of the intercostal tissue attenuation coefficients in SD and LE rats (over the 3.1 to 9.6 MHz frequency range); there was no temperature dependency in York pigs (over the 3.1 to 8.6 MHz frequency range). There was no significant temperature dependency of the intercostal tissue propagation speed in SD rats; there was a temperature dependency in LE rats and York pigs (-0.59, -1.6, and -2.9 m/s//spl deg/C for SD rats, LE rats, and York pigs, respectively). Even though the attenuation coefficient's temperature dependency was significant from the linear regression functions, the differences were not very great (-0.040 to -0.13, 0.011 to 0.18, and 0.055 to 0.10 dB/cm//spl deg/C for SD rats, LE rats, and York pigs, respectively, over the data frequency range). These findings suggest that it is not necessary to determine the attenuation coefficient of intercostal tissue at body temperature (37/spl deg/C), but rather it is sufficient to determine the attenuation coefficient at room temperature (22/spl deg/C, a much easier experimental procedure.


Title Attenuation of ultrasound in aqueous solutions of nucleic acids.
Author El'piner IY, Sadykhova SK, Braginskaya FI.
Journal Biofizika
Volume
Year 1970
Abstract We have studied the absorption of ultrasonic energy by solutions of nucleic acids, native and subjected to various treatments (chemical agents, heat, ultrasound of high intensity). For the measurements we used a pulse apparatus with a working range of 12-63 Mc/s. The following conclusion is drawn from the investigations. Change in the secondary structure of the RNA molecule by certain chemical agents (formaldehyde, hydroxylamine) leads to increase in the absorption of ultrasonic radiation while the ruptures in the chain of the polymer as a result of the action of ultrasound high intensity, hydrolysis and urea lead to reduction in the attenuation of the acoustic energy in the frequency range studied by us...


Title Attenuation of ultrasound in emulsions.
Author Kol'tsova IS, Mikhailov IG, Saburov B.
Journal Sov Phys Acoust
Volume
Year 1974
Abstract The absorption of ultrasound in mineral oil emulsions has been measured by a pulse technique at frequencies from 9 to 21 MHz. The additional absorption coefficient is investigated as a function of the concentration frequency, and temperature. The relative contributions of various mechanisms to the additional absorption of ultrasound in the emulsions are estimated.


Title Attenuation of ultrasound in homogenates of bovine skeletal muscle and other tissues.
Author Shore D, Miles CA.
Journal Ultrasonics
Volume
Year 1987
Abstract The attenuation of ultrasound in homogenates of bovine skeletal muscle and suspensions of myofibrils was measured over the frequency range 1.5–7 MHz, and found to be proportional to protein concentration in both. In the homogenates it varied with frequency and temperature in a similar way to the attenuation in post rigor muscle tissue; myofibrils showed a higher frequency dependence. The attenuation in homogenates of bovine muscle, liver and kidney and in suspensionsof myofibrils was measured over the pH range 3.5–13, and each showed a peak at about pH 11.5. This was thought to be due to a proton transfer process between NH3+ groups on the tissue proteins and OH− ions in the suspending fluid. A substantial peak at about pH 5 in the muscle and myofibril suspensions was not observed in homogenates of liver and kidney and was thought to be due to components of muscle that are absent from the other tissues. Myofibrils suspended in percoll solution of density 1.05 g cm−3, chosen to match approximately the density of the myofibrils, showed a slightly lower attenuation over the pH range 5–7, but a pH dependence similar to that of the myofibrils suspended in saline. The difference in the attenuations may be interpreted as the viscous component of the attenuation due to relative motion between the myofibril and its surrounding saline. The peak at pH 5 did not, however, appear to be due to the viscous loss mechanism peaking due to maximum shrinkage (and therefore maximum density) of the myofibril near this pH. The attenuation in homogenates of muscle was decreased by suspending in 0.5 M or 1.0 M rather than 0.1 M KCl. This may have been caused by the myosin filaments dissolving at high ionic strength.


Title Attenuation of ultrasound in normal liver and diffuse liver disease in vivo...
Author Maklad NF, Ophir J, Balsara V.
Journal Ultrason Imaging
Volume
Year 1984
Abstract Preliminary results of in vivo attenuation measurements of the liver have been obtained in 39 normal patients and in 35 patients with diffuse liver disease. A modified real-time sector scanner incorporating an online attenuation measurement method was used. The value of attenuation in normal liver was estimated as 0.52+or-0.03 dB/cm/MHz, measured at 3 MHz. Significantly higher attenuation values were obtained from patients with alcoholic and cardiac cirrhosis, and following hepatic artery infusion with chemotherapeutic agents. Lower values were obtained from patients with biliary cirrhosis, chronic active hepatitis, and diffuse infiltration by lymphoma or leukemia. Fatty infiltrated livers showed a wide range of values of 0.37-0.66 dB/cm/MHz. The results suggest that estimates of attenuation coefficients are useful in detecting the presence of diffuse liver disease.


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