It is the purpose of this study to inquire whether fetal gonadal development can be affected by low-level ultrasound. A preliminary study showed that 1 MHz ultrasound exposures at 10 W/cm² for 10 sec affected fetal gonads. The proposed study involves determining thresholds at which structural changes occur to fetal murine gonads. Following identification of ultrasound thresholds at which irreversible effects occur, light and electron microscopy of fetal gonads is investigated. The results of this study provide a basis for assessing risk incurred by fetal gonadal structures during exposure to ultrasound at both therapeutic and diagnostic procedures.

In medical applications the opportunity for reproductive tissues to become exposed to significant levels of ultrasound for appreciable periods of time is extant. This study involves determining threshold levels at which functional and/or structural changes occur to murine corporalutea. Following identification of thresholds and measurements of absorption coefficients, a second dose-effect study will assess multiple exposures. An electron microscopy study and a fertility study will be completed also. The results should provide a basis for assessing risk incurred by ovarian tissues during exposure to ultrasound at therapeutic and at diagnostic levels and regimes.

The use of ultrasound phased array, high-intensity focusing systems for ablation of tissue (surgery) allows electronic control of focal size and shape, as well as position, thus eliminating the necessity of a cumbersome mechanical scanning apparatus. While phased arrays have been employed for medical diagnostic and therapeutic applications (hyperthermia), they often require a prohibitively large number of elements. This study will determine if sparsely filled arrays, with the individual elements randomly located on the array surface, will facilitate the use of larger elements and spacing than used currently, reducing the number of elements and amplifiers required.

This pilot research study is aimed at the development of a dynamic dermofluorometer for the rapid and continuous recording of tissue fluorescence. Such an instrument should increase the diagnostic information provided by fluorescence tissue measurements when incorporated into a pharmacokinetic model of dye distribution. Thus, tissue fluorescence changes in response to exercise, localized heating, or drug therapy could be used to obtain dynamic information on the physiological state of tissue.

The general goal of this project is the development of improved teaching methods and materials for preparing science and mathematics teachers. The specific aim is to develop models and examples that incorporate new science and engineering instructional materials into teacher preparation courses for elementary and secondary education teachers. This effort is a collaboration between the College of Education and the College of Engineering at UIUC. Current advances in science, engineering, and bioengineering research in the College of Engineering are being transferred into teacher preparation courses and internships offered by the College of Education.

The objective of this project is a systematic study of the ultrasonic propagation properties of muscle using the scanning laser acoustic microscope. The study explores the acoustic heterogeneity of individual muscles and its relationship to the muscle's physical properties. The physical processes are known to affect muscle quality and the acoustic assessment is aimed at a noninvasive means to evaluate muscle quality.

Development of an Ultrasound-based Grading System to Enable Marketing Live Pigs on an Actual Value Basis
J. Novakofski* (Animal Sci.), W. D. O'Brien, Jr.,* F. K. McKeith* (Animal Sci.), R. N. Czerwinski
Illinois State Value-Added Program

The approach employed in this research examines the basic science underlying predication of meat quality and tenderness. The specific goal is the utilization of existing ultrasonic imaging technology to predict composition and quality of live pigs. The specific objectives are to compare measurements from digitized computer images of ultrasound scans, conventional hand measures from ultrasound scans, and actual measures from carcasses for prediction of carcass composition from loin eye and fat thickness; to examine the use of various linear measures of muscle dimensions and fat thickness in predicting composition; and to examine the use of various digital imaging parameters other than measures of fat or loin eye for predicting composition.

A major problem in marketing cattle is estimating the genuine value of an animal, which is determined by two factors: the quality of the meat the animal will produce and the quantity of retail product the animal will yield. Grading systems predict these characteristics to estimate true value. The objective of this project is to evaluate thoroughly a large number of established ultrasound methodologies and estimate the degree to which these ultrasound methodologies can be used to predict objectively yield and quality of beef cattle.

The objective of the research program is to develop the basic acoustic propagation and backscattering database to evaluate the acoustic imaging tradeoffs for detecting and characterizing buried artifacts in ground soil.

The specific research aims are to measure the ultrasonic energy delivered to the human ovary, early embryo, and mid-trimester fetus using currently available diagnostic imaging equipment. Specially designed hydrophones will be placed as close as possible to the ovaries in normal volunteers. Exposure to the embryo will be determined by placing the hydrophones as close as possible to the embryo in utero. Once the dosimetry in these clinical situations has been established, then meaningful data regarding the effect of diagnostic ultrasound in human pregnancy can be obtained and ``safe'' levels of ultrasonic energy established for patients of varying size and gestation.

It is estimated that well over half of all human pregnancies are evaluated with ultrasound. Although this imaging modality has continued to demonstrate a very safe record, vigilance dictates that we continue to evaluate the potential for risk to the fetus. The long-term objectives of this research program are to evaluate the safety of diagnostic ultrasound and pulsed Doppler ultrasound in an in vivo system similar to the human and to observe if changes in animals exposed prenatally to ultrasound are the same for pulsed Doppler ultrasound. The study incorporates a nonhuman primate as a model for the human and a commercial ultrasound imaging system.

The objective of this project is to systematically evaluate the application of ultrasound to predict objectively yield and quality of beef cattle. A sophisticated ultrasound grading system is being developed and the system will be evaluated with 120 cattle. This is being conducted with an interdisciplinary team effort involving research scientists from the Bioacoustics Research Laboratory in the Department of Electrical and Computer Engineering and the Meat Science Laboratory in the Department of Animal Sciences and with research scientists at Mayo Foundation, Rochester, Minn. and Riverside Research Institute, New York, N.Y.

The objective of this research is to evaluate theoretical tissue temperature increases due to focused diagnostic ultrasound fields under various realistic tissue models. The approach is to apply the point-source, harmonic, spherical solution of the linear acoustic wave equation to the appropriate source aperture geometry for the particular tissue model, from which the general acoustic pressure field distribution is obtained. The tissue transient and steady-state temperature increase are then calculated by applying the point-source solution of the bioheat transfer equation to the calculated field distribution.

The objective of this research is to estimate quantitatively tissue elasticity using ultrasound. Compressibility, lesion mobility, and other tissue viscoelastic properties depend on the estimation of tissue displacement. Estimating tissue displacement from conventional diagnostic ultrasonic B-scans under known forcing functions has considerable application in the diagnosis of cancer because various types of cancer lesions exhibit different elastic moduli.

The long-term objective is to further the state of the art of detecting defects that will compromise the integrity of new types of food packages by using a research team approach (experts in packaging, acoustic imaging, and challenge testing). The SLAM technology also operates at much higher frequencies (commercially available up to 500 MHz), thus providing the capability of achieving resolution limits of 4µm. The short-term objective of this pilot study is to identify the fundamental resolution limit by the Bioacoustics Research Laboratory's SLAM (operates at 100 MHz) of detecting packaging defects in order to develop a theoretical basis to improved image resolution capabilities.

This is a collaboration between the electromagnetics group and the bioacoustics group in the Department of Electrical and Computer Engineering. The electromagnetics group has developed some computational imaging algorithms that can potentially enhance ultrasonic images. The bioacoustics group has evaluated aspects of the ultrasound diffraction tomography problem. This research is aimed at combining the joint expertise to evaluate nonlinear inverse scattering problems.

The long-term goal of the proposed work is to create the knowledge needed to design neurotrophic surfaces with micro- or macropatterns of selective substrates which promote or retard adhesion, growth, extension, or connection of specific neuronal and glial cells. This technological capability will facilitate the study of basic neuro science, including neural development, electrical and chemical communication among small populations of neurons, and cell culture models of learning and memory.

Applications for microelectrical-mechanical systems (MEMS) which are being developed include low-cost microoptical mechanical switches for telecommunications, mechanical devices for microsurgery, and masks for biological molecule deposition. This project is aimed at high-force and displacement devices, as well as using dissimilar materials and creating 3-D utility from planar elements. One approach is to combine wafer-scale and laser-material processing to join elements which cannot be fabricated in the same process as silicon. Research in silicon and laser-material processing is currently being developed to solve the fundamental issues of MEMS.

Neuronal pattern analysis documents the dynamic brain processes of sensation, perception, learning, and cognition by recording the electrical activity of brain neurons. Recent advances in multiarray recording have greatly expanded the rate at which these data can be obtained, making possible the study of dynamic intercorrelations in neuronal networks. Computational modeling has fostered major increments in data-processing requirements, which call for parallel development of adequate database systems for organization, rapid access, and sharing of these data. This work establishes a database system for time series neurophysiological data recorded by the Neuronal Pattern Analysis Group at the Beckman Institute, carried out with collaboration from the National Center for Supercomputing Applications.

Neural net and other pattern recognition techniques are to be used to analyze Fourier transform infrared photo acoustic spectroscopic (FTIR-PAS) data from samples of corn in order to automate the detection of contaminated corn.

We propose to use morphological and morphometric, electrophysiological, immunocytochemical, and behavioral methods in mature adult and aging cerebellar cortex to determine which synapse and neuron types in cerebellar cortex exhibit plasticity in response to learning and to physical exercise; which nonneuronal elements exhibit plasticity; the molecular mechanisms underlying this plasticity; and functional correlates.