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
 Thursday, March 28th, 2024
BRL Home
About BRL
Publications
Projects
People
History
Facilities
Abstracts Database
Seminars
Downloads
Archives
Bioengineering Research Partnership
William D. O'Brien, Jr. publications:

Michael L. Oelze publications:

Aiguo Han publications:

BRL Abstracts Database

Search - a quick way to search the entire Abstracts Database.
 
Advanced Search - search specific fields within the Abstracts Database.
Title
Author
Journal
Volume
Year
Abstract Text
Sort by:     Title     Author     Journal     Year
Number of records to return:     10     20     30     50

Your search for ultrasound produced 3296 results.

Page 38 out of 330

Title An ultrasound imaging system.
Author Banks LW.
Journal Hewlett-Packard Journal
Volume
Year 1983
Abstract No abstract available.


Title An ultrasound power meter.
Author Engan H.
Journal J Acoust Soc Am
Volume
Year 1982
Abstract An ultrasound power measuring method based on measurement of the radiation force is described. The method requires no target to measure this force since the force is measured at the holder of the ultrasonic transducer that is transmitting. The actual power meter reported is based on modulated acoustic transmission to facilitate electronic detection and measurement.


Title An unusual flat interface in orbital ultrasonic examinations.
Author Dadd M, Kossoff G, Hughes H.
Journal Ultrasound Med Biol
Volume
Year 1976
Abstract Systems of classifying orbital echograms have been developed to aid in increasing the diagnostic accuracy of the technique. An unusual flat interface was recorded in the retrobulbar region of three patients and in each case shown to be a horizontal plane separating two fluid regions. The dynamic behaviour of these regions was studied in one patient over a 30 min period and possible interpretations of the phenomenon discussed. In the other two patients the interface was restricted to one tumour lobule. The characteristic appearance described has been added to our diagnostic criteria and we expect it to add to the value of the technique in diagnosis of orbital pathology.


Title Analyses and predictions of ultrasound interactions with model biomembrane systems via two-state transition model.
Author Tata DB.
Journal Thesis(PhD): Univ of Illinois
Volume
Year 1991
Abstract Low intensity ultrasound (approximately 10 to the ?6 W/cm*cm) in the frequency range of 0.5 MHz to 5.0 MHz was employed to investigate biomembrane structural relaxation kinetics via absorption and velocity dispersion spectroscopy. The multilamellar vesicles utilized in this investigation were either composed of pure phospholipids or mixtures of phospholipids and small molar fractions of protein gramicidin. The experimental findings reveal enhanced ultrasound interactions near to the lipid phase transition temperature. The enhanced ultrasound absorption spectra closely resemble single relaxation spectra, suggesting that the membrane constituents under go a simple two-state transition. The temperature dependence of the relaxation frequency is followed with the combined aid of the absorption and velocity dispersion spectrum. Thermodynamic and electrical capacitor two-state transition models are developed to help describe the observed phenomena and to predict to a reasonable degree of accuracy the enhanced findings promoted by ultrasound.


Title Analysis and design of ultrasound phased arrays for hyperthermia cancer therapy.
Author Ibbini MS.
Journal Thesis(PhD): Univ of Illinois
Volume
Year 1988
Abstract Acoustic phased arrays, which can be focused and steered electronically, offer an attractive to the mechanically scanned focused ultrasound systems currently in use in hyperthermia cancer therapy. However, both electrical and mechanical scannings require a very intense focal spot which could increase the risk of unwanted nonthermal effects such as cavitation. In addition, hot spots proximal to the tumor may occur because of the near-field beam overlapping due to scanning. This thesis introduces a new method which will allow the direct synthesis, without scanning, of the more diffuse heating patterns useful in hyperthermia. Two quite different phased arrays are theoretically evaluated as hyperthermia applicators: a concentric ring array (CRA), and an NxN square-element array. The new synthesis method is based on the conjugate phase and amplitude matching techniques often used in optics. The field conjugation method (FCM), theoretically capable of tailoring the ultrasonic power deposition to virtually any tumor geometry without scanning, offers also the possibility of simultaneously focusing at different locations. The multiple focusing feature is combined with a new phasing technique involving angular phase rotation to eliminate hot spots that are often associated with the synthesis of annular patterns. A concentric-ring array was chosen because of its ability to directly produce annular patterns with a minimum number of array elements. However, computer simulations demonstrated that the use of directly synthesized annular intensity profiles for heating could be severely limited due to the formation of undesired hot spots along the array axis. A new method, based on combining the multiple focusing feature and a simple mechanical movement of the applicator, is proposed as a means of heating different size tumors at various depths. While a concentric-ring array is limited to the synthesis of annular and spot foci, an NxN square-element array is investigated as a means of synthesizing heating patterns with or without circular symmetry. Simulated heating patterns produced by the FCM are compared to those produced by electronic scanning. Although the two techniques result in equivalent power deposition patterns, the SPTP focal intensity associated with the FCM is substantially lower than that used for scanning. A method is also proposed to combine the FCM with electronic scanning to produce more complicated diffuse heating patterns. The advantage of this method is to minimize the number of scan points and, hence, to use a lower SPTP intensity. Moreover, an 8x8 square-element phased array prototype built and radiation patterns produced by single and multiple elements were measured, and agreed well with theoretically predicted patterns. To evaluate the different applicators, the steady state bioheat transfer equation was solved using a finite difference technique. The simulated temperature distributions associated with different power deposition patterns demonstrate the potential of the field conjugation technique for the design of diffuse heating patterns for hyperthermia cancer therapy.


Title Analysis and measurement of ultrasound backscattering from an ensemble of scatterers excited by sine-wave bursts.
Author Sigelmann RA, Reid JM.
Journal J Acoust Soc Am
Volume
Year 1973
Abstract This paper develops a practical approximation for the backscattering of periodic bursts of sine waves by a volume of randomly distributed scatterers. The approximation is applied to the measurement of a "volumetric backscattering cross section," using a substitution method in which the rms value of the gated backscattered signal is compared with the rms value of a wave reflected from a target of known coefficient of reflection. It is shown that the signal backscattered from the ensemble depends on the attenuation of the wave in the volume and upon the burst and gate lengths. An equation to obtain the volumetric backscattering cross section from experimental data is derived.


Title Analysis of a multielement ultrasound hyperthermia applicator.
Author Benkeser PJ, Frizzell LA, Goss SA, Cain CA.
Journal IEEE Trans UFFC
Volume
Year 1989
Abstract An unfocused multielement ultrasound applicator was developed for hyperthermic treatment of superficial tumors. The applicator contains sixteen 3.8-cm-square individually controllable elements on a 15.2-cm-square piezoelectric ceramic plate. The acoustical power output of each element can be independently applied to facilitate uniform heating throughout the treatment area while minimizing undesired heating in normal tissues. The performance of the applicator was examined by measuring acoustical power output and beam profiles. The results of this analysis indicated that the applicator is capable of producing required therapeutic output levels with excellent localization and control of the power deposition.


Title Analysis of coronary ultrasound thrombolysis endpoints in acute myocardial infarction (ACUTE trial)..Results of the feasibility phase.
Author Rosenschein U, Roth A, Rassin T, Basan S, Laniado S, Miller HI.
Journal Circulation
Volume
Year 1997
Abstract BACKGROUND: It has been demonstrated that therapeutic ultrasound effects ultrasound thrombolysis by selectively disrupting the fibrin matrix of the thrombus. This study was conducted to evaluate the clinical feasibility of percutaneous transluminal coronary ultrasound thrombolysis in acute myocardial infarction (AMI). METHODS AND RESULTS: Consecutive patients (n = 15) with evidence of anterior AMI and Thrombolysis in Myocardial Infarction (TIMI) grade 0 or 1 flow in the left anterior descending artery underwent coronary ultrasound thrombolysis. Angiographic follow-up was performed after 10 minutes and 12 to 24 hours. Ultrasound induced successful reperfusion (TIMI grade 3 flow) in 87% of the patients. Adjunct percutaneous transluminal coronary angioplasty (PTCA) after ultrasound thrombolysis produced a final residual stenosis of 20 +/- 12% as determined by quantitative coronary angiographic analysis. There were no adverse angiographic signs or clinical effects during the procedure. There was no change in the degree of flow in any of the patients at the 12- to 24-hour angiograms. During hospitalization, 1 patient had recurrent ischemia on the fifth day after the procedure, and emergent catheterization revealed occlusion at the treatment site. The patient was successfully treated with PTCA. CONCLUSIONS: These results suggest that.ultrasound thrombolysis has the potential to be a safe and effective catheter-based therapeutic modality in reperfusion therapy for patients with AMI and other clinical conditions associated with intracoronary thrombosis. Comments: Comment in: Circulation 1997 Mar 18;95(6):1360-2.


Title Analysis of focusing action of spherically curved transducers.
Author Kossoff G.
Journal Ultrasound Med Biol
Volume
Year 1979
Abstract A technique to determine the focusing action of spherically curved transducers is described. In the method a universal set of curves for the axial intensity and the beamwidth is obtained by specifying all of the dimensions in terms of the transition distance from the near to the far field of the equivalent flat transducers and these curves illustrate graphically the focusing action of the beam.


Title Analysis of in vitro sarcoma population reduction due to combined effects of hematoporphyrin with ultrasound via first order rate kinetics.
Author Tata DB, Dunn F.
Journal Jpn J Med Ultrason
Volume
Year 1991
Abstract Enhanced in vitro sarcoma cell reduction during the application of ultrasound with the photo activated anti-cancer drug hematoporphyrin [HP] has been reported in which the cell damage enhancements are attributed to short lived singlet oxygen molecules generated via ultrasonically activated HP molecules. In the present communication, first order rate kinetics are utilized to reveal the dominant role HP plays in reducing the population rapidly. The first order rate constant of in vitro population reduction due to the presence of HP is found to be directly proportional to HP concentration, and to the intensity of the sonication. The total fractional in vitro population reduced by HP is found to obey a power law in which the exponent is a linear function of the ultrasound intensity and a non-trivial function of the concentration of HP.


Page 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119 | 120 | 121 | 122 | 123 | 124 | 125 | 126 | 127 | 128 | 129 | 130 | 131 | 132 | 133 | 134 | 135 | 136 | 137 | 138 | 139 | 140 | 141 | 142 | 143 | 144 | 145 | 146 | 147 | 148 | 149 | 150 | 151 | 152 | 153 | 154 | 155 | 156 | 157 | 158 | 159 | 160 | 161 | 162 | 163 | 164 | 165 | 166 | 167 | 168 | 169 | 170 | 171 | 172 | 173 | 174 | 175 | 176 | 177 | 178 | 179 | 180 | 181 | 182 | 183 | 184 | 185 | 186 | 187 | 188 | 189 | 190 | 191 | 192 | 193 | 194 | 195 | 196 | 197 | 198 | 199 | 200 | 201 | 202 | 203 | 204 | 205 | 206 | 207 | 208 | 209 | 210 | 211 | 212 | 213 | 214 | 215 | 216 | 217 | 218 | 219 | 220 | 221 | 222 | 223 | 224 | 225 | 226 | 227 | 228 | 229 | 230 | 231 | 232 | 233 | 234 | 235 | 236 | 237 | 238 | 239 | 240 | 241 | 242 | 243 | 244 | 245 | 246 | 247 | 248 | 249 | 250 | 251 | 252 | 253 | 254 | 255 | 256 | 257 | 258 | 259 | 260 | 261 | 262 | 263 | 264 | 265 | 266 | 267 | 268 | 269 | 270 | 271 | 272 | 273 | 274 | 275 | 276 | 277 | 278 | 279 | 280 | 281 | 282 | 283 | 284 | 285 | 286 | 287 | 288 | 289 | 290 | 291 | 292 | 293 | 294 | 295 | 296 | 297 | 298 | 299 | 300 | 301 | 302 | 303 | 304 | 305 | 306 | 307 | 308 | 309 | 310 | 311 | 312 | 313 | 314 | 315 | 316 | 317 | 318 | 319 | 320 | 321 | 322 | 323 | 324 | 325 | 326 | 327 | 328 | 329 | 330