A description is given of an L.E.D. light panel display powered by an Electroencephalograph machine with some of its applications. The EEG machine powers a panel array of lights displaying electrical brain waves picked up by corresponding head probes. This new method discloses brain wave signal phase relationships, frequency, intensity, and areas of activity to medical technical personnel. The lights are arrayed exactly as the sensing probes are arranged on the head of the person being examined. The panel array itself is composed of light emitting diodes (LEDs) powered by the brain wave signals from the output amplifiers of the EEG machine. The LED lights require little power and are capable of frequencies well beyond those encountered in the human brain. These frequencies of from 1/2 Hertz to 60 Hertz and their associated amplitudes are very perceptable to the human eye when displayed on the panel as flickering lights. The use of the SIDI in conjunction with the permanent electroencephalogram provides the medical technical analyst with immediate interrelated multichannel information in a readily comprehensable form.
The utility of coded aperture imaging of radioisotope distributions in Nuclear Medicine is in its ability to give depth information about a three dimensional source. We have calculated imaging with Fresnel zone plate and multiple pinhole apertures to produce coded shadows and reconstruction of these shadows using correlation, Fresnel diffraction, and Fourier transform deconvolution. Comparisons of the coded apertures and decoding methods are made by evaluating their point response functions both for in-focus and out-of-focus image planes. Background averages and standard deviations were calculated. In some cases, background subtraction was made using combinations of two complementary apertures. Results using deconvolution reconstruction for finite numbers of events are also given.
Irradiation of brain tissue with a He-Cd U.V. laser microfluorimeter (325 nom) disclosed the presence of endogenous fluorochromes in discrete brain structures. The in situ emission spectra were measured and the fluorescence was recorded photographically. The fluorochromes were found to have properties similar to those of bioamine-aldehyde condensation products. In addition, observations were made which suggested that axonal transport of these fluorochromes occurs.
Scattering pattern analysis for an ensemble of heterogeneous particles in a tenuous solution is applied to species identification and concentration estimation of bacteria with a view toward the development of a rapid automated technique to identify and count bacteria in urine. The scattering patterns measured with latex spheres and bacteria (Escherichia coli and Staphylococcus aureus) agree well with the theoretical calculations by the Mie theory and the Rayleigh-Debye approximation modified for size distributed and randomly oriented scatterers. The parameters (average size, axial ratio, size variation, refractive index) estimated in the scattering pattern analysis are reasonable. The sensitivity of the scattering pattern for the aggregation of scatterers is shown. Turbidimetry is improved by using the average total cross section calculated with the above parameters. The concentrations of above bacteria are estimated by this technique. They agree within a factor of 10 with the counts obtained by conventional plate count technique in a clinical microbiology laboratory. This error is acceptable for most practical applications of bacteria count in urine. Thus, the usefulness and effectiveness of the scattering pattern analysis in some of the practical applications are shown.
Poliovirus type I, strain LSc2ab, has been grown in HeLa cell cultures and purified by means of a five-step process involving cell debris removal, virus precipitation with polyethylene glycol 6000, ultrasedimentation into a discontinuous CsCl step gradient, chloroform extraction in the hypertonic state, and isopycnic density gradient centrifugation. Virus concentration of 1.5-3.0 mg/ml in 20 μliter samples was achieved by volume reduction. Laser-Raman spectra of the purified samples exhibit characteristic lines which can be assigned to the viral coat protein and the RNA. Because characteristic spectral "fingerprints" can be obtained in a matter of minutes, it may be possible to develop a method of rapid viral analysis based upon molecular spectroscopy. Our study shows for the first time that a human virus can be identified by Raman spectroscopy.
An optical microscopic instrument is described that will allow visual observation and photoelectric detection measurement and classification of moderate concentrations of viruses in biological fluids in a few minutes. The instrument combines fluorescence correlation spectroscopy and ATR fluorescence with special electronics and a correlator fast Fourier transform data system to measure the size of viral particles while disregarding background objects found in typical biological fluids. Further data processing allows calculation of the nucleic acid mass of individual particles and their total concentration. A novel chemical procedure is employed to differentiate various types of viral nucleic acid. The combination of these measurements is then used to classify a virion without requiring the use of a specific antibody for it. Calibration of the system against test objects and compounds, as well as measurements on several virus types will be shown.
Techniques in nondestructive testing may be suitably modified for use in dental research. Described are dental applications of real-time holographic interferometry and laser-optical topographic mapping. Dentistry has depended upon physical replicas, such as plaster casts and models, to duplicate the human dentition for the diagnosis of oral pathology, and for the fabrication of dental prostheses. The application of modern optical techniques for remote measurement may provide alternate improved treatment methodologies, including the acquisition of data suitable for computer analysis and numerical controlled automated prostheses fabrication. Interferometric fringes may be generated, and perceived in real-time, by deforming or displacing a dental object upon which is superposed the holographically reconstructed virtual image of the object in its original condition. Various designs of removable partial denture prostheses frameworks were stressed while seated on models of the human dentition. Fringe patterns were generated in a repeatable sequence during intermittent localized stressing of the prostheses, and were simultaneously recorded using a low-light-level video system. Applications of intra-oral topographic mapping using laser optically generated grids, and examples of numerical controlled milling of replicas of tooth surfaces, are briefly described.
In 1962 Chance demonstrated the feasibility of monitoring intramitochondrial NADH levels in vivo. NADH serves as an indicator of oxidative metabolism because it fluoresces at 475 nm while its oxidized form NAD+ does not fluoresce significantly. We have designed a long focal length television fluorometer for the direct measurement of NADH fluorescence in the operating room on a practical basis. It enables a comparison of simultaneous metabolic changes in several anatomic areas. The 30-cm working distance of the system permits metabolic measurements to be made with a minimum of interference with normal operating procedures and other instrumentation. The tissue is illuminated at 360 nm by a mercury arc lamp, and the resulting fluorescence is monitored by a television system. Fluorescence variations are then analyzed by video densitometric techniques to localize metabolic changes that occur on a regional basis. Intravenous sodium fluorescein provides a reference fluorescence at 529 nm to compensate for the absorption of the ultraviolet excitation light by the hemoglobin in the blood. The difference between the fluorescence at 475 nm and 529 nm represents a corrected NADH fluorescence signal related to local oxidative metabolism. By employing this system in conjunction with other instrumentation, we have demonstrated a strong correlation among NADH fluorescence, oxygen consumption, and potassium kinetics in exposed cerebral cortex. Additionally, some effects of ischemia on NADH fluorescence were studied in both cortex and myocardium.
Novel use is made of multiple 20 and 65 μm optic fibers coupled to LEDs to provide light stimuli in specific spatial configurations to a visual nervous system. The LEDs' currents, hence output light intensities, are modulated in a Gaussian white-noise fashion to utilize techniques, developed by Wiener, for computing nonlinear generalizations of the impulse response function for the visual system. In particular, nonlinear spatial crosstalk between adjacent regions of a crustacean eye are examined using so-called Wiener kernels. The optical and computational techniques are useful for a wide variety of research areas and are easily extended to them.
The use of the close-range technique in biostereometrics has created the need for a simple, precise universal stereometric camera system. The Kelsh K-460 Stereometric Camera has been designed to fill this need. The camera focusing distance of 360mm to infinity covers a broad field of close-range photogrammetry. The design provides for a separate unit for the lens system and interchangeable backs on the camera for the use of single frame film exposure, roll-type film cassettes, or glass plates. The system incorporates the use of the surface contrast optical projector (SCOP) developed at the Biostereometrics Laboratory, Baylor College of Medicine.
The basic determinants required for accurate estimation of the functional status of the intact heart, lungs and other organs; namely, their true dynamic changes in regional shape and dimensions, the temporal and regional distribution of blood flow to, within, and from these organs, and their internal and transmural pressures, can be obtained by application of dynamic spatial reconstruction techniques to simultaneous and synchronous recordings of multiplanar x-ray images and multiple associated physiological variables. This paper describes a computerized method for obtaining cross-sectional images of the dynamic spatial distribution of x-ray attenuation covering the entire anatomic extent of the thorax and its contents in living dogs with 1 mm resolution and at 1/60th second intervals in time. Operator-interactive computer programs for display of the dynamic sequences of these reconstructed cross sections, for display of any desired single or spatially related set of coronal, sagittal or obliquely oriented section(s) calculated from these reconstructed cross sections, and for display of the three-dimensional surface of the entire organ structure are operational for viewing the temporal and spatial distribution of contraction, expansion, and perfusion of the heart, lungs, and other organs over their full anatomic extent from various aspects and in variable time-base modes ranging from stop-action to real-time. The results achieved with this computerized system for three-dimensional reconstruction and display of the heart, lungs, and circulation demonstrate the potential for providing greatly improved techniques for investigation of the relationships of the dynamic three-dimensional structure of these and other organ systems of the body to their regional and integrated function.
Various means have been devised for quantifying human athletic performances, but only cinematography leaves the human subject entirely free to perform the activity of interest. Photographic techniques have been used to quantify human motion since at least 1930, but it was not until the early 1970's that attempts were made to quantify such motions in three dimensions. Until recently no viable technique existed for quantifying human athletic performance in three dimensions. Early techniques placed tight constraints on camera placement and orientation and were never carefully validated. An attempt has been made to develop a "close-range cinephotogrammetry" for solving the three dimensional problem. The fundamentals of the analysis are outlined and the results of preliminary validations presented. A variety of problems specific to photo-analysis of the human body are discussed and some suggestions for further improvements are made.
A new kind of camera has been devised which records depth profiles of scenes directly on photographic film. If the object surface is described by S(x, y, z), where z is the depth dimension, then a normal photograph records ∫s(x, y, z)dz The new camera might record S(xo, y, z) or S(x, yo, z) where xo and yo are easily variable parameters. Many such profiles in rapid succession provide a full 3D record of the scene. The camera uses a slit in an ordinary image plane to restrict the x or y information and laser rangefinding with a modelocked laser to obtain the z information. Depth resolution of one mm or less is achievable. Applications to whole body imaging and internal 3D photography are discussed.
An investigation was made into the employment of a photogrammetric technique to determine the treatment surface topography of patients undergoing radiotherapy. A suitable technique that meets criteria of simplicity and accuracy is described. Simplification is achieved by utilizing the source light of the radiotherapy unit to project a pattern that serves to complete a stereo pair with a photograph. Accuracy of the order of 2 mm. was obtainable with a test space. An example with a human form is presented.
A relatively new x-ray imaging technique, xerography, gives very detailed, high contrast images. It is particularly useful in detecting texture changes associated with early breast cancer. We describe a process of digitally scanning photographs of these xeromammograms. Normalization of the data representing the breast images is necessary to later classification; four methods were used for our study. The visual appearance of certain abnormal texture is described and used to motivate our statistical measures of texture. One group of measurements is derived from density value histograms; a second group depends on a density value co-occurrence matrix; a third group computes statistics from a gradient of the image; the last group analyzes the number of connected paths in the image. Nineteen features are collected from these measurements and are evaluated by using them to classify abnormal from normal tissue in a set of four test cases.
A computer hardware-software system has been developed for extracting optical and digital mea-surements from chest x-rays and using these measurements to classify the severity of lung disease. The system consists of a digital image scanner and an optical system consisting of an x - y controller for film transportation and an RSI Fraunhofer diffraction pattern sampling unit. Initially the classification has been of opacity textural patterns associated with coal workers pneumoconiosis (CWP). However, the system appears to be expandable to all diseases described in the international standard which include lung disease, heart disease, and cancer with only software modification. Recently extensions to large opacity detection, measures of lung vascularity and lung and heart volume have been made. Results indicate classification accuracy rates for pneumoconioses comparable to visual readings of the films by expert radiologists, and significantly better than non-radiologist physicians who often read these films.
Muscle biopsy is an important tool in the diagnosis and study of neuromuscular disease. Modern histo-chemical techniques produce specimens in which the "fast" and "slow" fibers appear visibly different in color. Certain neuromuscular diseases cause the sizes and relative numbers of each fiber type to change. Neurologists use these changes to diagnose the type and severity of disease. This analysis can be either subjective, and hence of limited accuracy, or quantitative and painstakingly tedious. Working in collaboration with the University of Southern California Neurology Department, the Jet Propulsion Laboratory is developing a compact computer system to perform quantitative muscle biopsy analysis quickly and accurately. The system feeds the microscope image into the computer which then isolates and counts the fibers and measures their size. It then prints out graphs showing the size distribution for each type fiber. This information will assist physicians in diagnosing and treating muscle disease and will facilitate research aimed at understanding human muscle disease processes.
Cardiogenic pulmonary edema is a major cause of pulmonary edema. With methods presently available, pulmonary edema can only be detected clinically, late in its course, making prompt therapy of the developing condition virtually impossible. The detection of an early rise in pulmonary venous pressure could allow institution of therapy and possibly prevent pulmonary edema and its accompanying morbidity and mortality. It has been shown experimentally that as pulmonary venous pressures rise, there is a redistribution of blood flow in the lungs. A prototype optical-digital system for automatic processing of coal worker's pneumoconiosis chest radiographs has been developed. With the optical system it is well known that high frequency information pertains to the amount of sharpness of edge information in an image. From experience with the prototype system, it was hypothesized that lung regions with more vascularity would generate more of this high frequency than a region of lung with few vessels, and that pulmonary vascular patterns could be extracted using the Fraunhofer diffraction pattern sampling unit. To examine the effect of the number of vessels in annular ring and wedge signatures, a study was made of straight line patterns which might simulate different categories of redistribution. Different patterns were characterized by plotting the normalized energies of the annular rings and wedges. An interactive, non statistical prediction was made on a test set of line patterns with an accuracy rate of 95%. Spatial frequency signatures were recorded using radiographs, carried out by removing an upper lung and lower lung region. These regions were rotated and interchanged and these signatures were recorded. Interactive, non statistical predictions were made on a test set of these radiographic sections with an accuracy rate of 90%. Derived features from a test set of 15 normal and 24 abnormal (2+ re-distribution) radiographs were submitted to a non-interactive stepwise discriminant analysis procedure (BMDO7M) which yielded an accuracy rate of 95% using three features. These preliminary results are encouraging and suggest that automatic processing of chest radiographs might yield estimates of the pulmonary venous pressure.
A computer system has been developed to quantify the degree of atherosclerosis in the human femoral artery. The analysis involves first scanning and digitizing angiographic film, then tracking the outline of the arterial image and finally computing the relative amount of roughness or irregularity in the vessel wall. The image processing system and method are described.