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Rotational and translational movement features of the pelvis and thorax during adult human locomotion.

The kinematics of the pelvis and thorax are important in gait studies since their movement patterns are closely related to gait efficiency and 'smoothness' of locomotion. The purpose of this study was to identify features of normal gait patterns for later comparisons with pathological and developmental gait patterns. A two camera SELSPOT system interfaced with an HP1000 minicomputer was used to obtain three-dimensional kinematic/temporal data for the pelvis and thorax. Data from treadmill walking of eight adults were used for within subject (at different speeds) analyses. The analyses revealed a very complex pattern with a set of breakpoints which was consistent over all subjects. Some features were invariant over a range of walking speeds although the total range of motion changed considerably.

Adult↗

Bedside serial comparison of electrocardiograms.

A unique method for serial comparison of electrocardiograms is introduced. A Siemens 440 or 740 electrocardiograph can be linked directly to a central minicomputer system, from which serial data for up to three previously recorded ECGs from the same patient can be retrieved and transferred back to the ECG machine. Serial comparison logic has been incorporated into the diagnostic program inside the 440 and 740 so that immediate serial comparison can be undertaken at the bedside or in the clinic.

Computers↗

A computer-based data analysis system for enzyme-linked immunosorbent assays.

A computerized system is presented for automating the data collection, processing, and displaying tasks involved in enzyme-linked immunosorbent assays. This system uses a through-the-well absorbance reader of microtiter plates interfaced to a minicomputer running the UNIX operating system. Optical density in each well of a 96-well microtiter plate is recorded as a function of time for up to 10 time points. These data are automatically transmitted to the remote computer. The rate of product formation is then calculated for each well, and a battery of analysis, display, and comparison programs can then be used by the researcher for data presentation. Using the initial rate of reaction as the basis for quantifying enzyme-linked immunosorbent assays focuses on the catalytic property of the enzyme and allows a large dynamic range of the assay on any plate. These programs can be adapted to virtually any mini- or microcomputer with a graphics display or a plotting device. Assuming moderately powerful computing hardware, throughputs of 50 plates per day are easily achieved. The programs work equally well with peroxidase, beta-galactosidase, or alkaline phosphatase conjugated second antibodies, and with whole cell or soluble antigens.

Antibodies, Monoclonal↗

A comparison of estrogen and androgen receptor levels in human prostatic tissue from patients with non-metastatic and metastatic carcinoma and benign prostatic hyperplasia.

Estrogen receptors (ER, N = 72) and androgen receptors (AR, N = 33) were determined by high pressure liquid chromatography (HPLC) in 72 human prostatic tissues obtained at prostatectomy, and exploratory statistical analyses of the resulting data were performed. To facilitate use of these data as well as other pertinent information from the patient charts, a program for a comparatively large data base was implemented on a Wang minicomputer. The median values of cytosolic AR in the four cancer stages examined were statistically different from each other (P = 0.01), with AR increasing from stages A through D. Even though ER differences between the four stages were not significant (P = 0.13), there was a trend, in the data examined, for median ER values to decrease with stages B through D. On the other hand, median BPH values for both ER and AR were found to lie mid-scale compared with the respective cancer stages, leading to the conclusion that receptor measurements probably cannot distinguish between CA and BPH in human prostatic tissue, at least as measured by competitive binding techniques.

Binding, Competitive↗

The real time processing of dynamic physiological signals.

A signal processing system has been developed consisting of a microcomputer linked to a minicomputer. The system has been designed to allow ease of development of programs for processing physiological signals in real time. The system also allows extensive non real time processing to be carried out and the generation of graphical displays. Some of the problems involved in producing real time signal processing programs are discussed. The problem of computing the beat by beat mean pressure in real time is described as an example.

Blood Pressure Determination↗

Head movements and actographic recordings in free-moving animals, using computer analysis of video images.

A method is described to record the X,Y-coordinates of two bright spots on a TV image. These spots are produced by a light-emitting diodes (LEDs) assembly, which must be affixed on the moving target. The system was developed to record head movements of free-moving animals, chronically implanted to bear a socket LEDs holder, but it can be easily adapted to other applications, such as the measure of limb displacements in Man. Recordings are allowed up to 25 frames per second with an approximate spatial resolution of 255(X) X 300(Y). The method, which is based on standard TV equipment, involves a hardware interface, feeding the X and Y counts into a laboratory minicomputer and data acquisition software. A sample record is shown and other applications are discussed in relation to current non-video and video actographic techniques.

Animals↗

Video and scanning microdensitometer-based imaging systems in autoradiographic densitometry.

The characteristics of computer-assisted imaging devices (CIDs) incorporating charge-coupled device cameras, vidicon cameras and scanning microdensitometers (SMDs) are compared. Advantages of vidicons include their low cost, the option of real-time imaging, continuously variable optical magnification and the wide choice of available vidicon elements. Disadvantages include densitometric non-linearities and, with some vidicons, lack of dynamic range. A CID comprising a laboratory minicomputer, image processing device, vidicon and SMD scanners and our 'PANDA' image analysis routines is described. Software corrections for vidicon errors are evaluated by comparing the densitometric accuracy of the CID receiving input from the vidicon camera and from the SMD. The scanners exhibit similar densitometric accuracy and linearity, and acceptable between-session repeatability. It is concluded that densitometric precision of a corrected vidicon scanner is not the limiting factor for quantitative autoradiographic densitometry.

Animals↗

Development and applications of an interactive digital filter design program.

We have implemented an interactive digital filter design program in the HP 1000 computer at the Department of Electrical Engineering of the University of Washington. This program allows users to design different types of filters interactively with both amplitude and phase responses displayed on graphic devices. The performance of each designed filter can be evaluated conveniently before the best one is chosen and implemented for any particular application. This program can design recursive filters, e.g. Butterworth, Chebyshev and elliptic, or nonrecursive filters with one out of six different windows, i.e. rectangular, triangular, Hann, Hamming, Blackman and Kaiser. The main outputs from this program are coefficients of a transfer function of an analog filter, a digital filter, or both. Therefore, the design of both analog and digital filters is facilitated by using this program. The program is very simple to use and does not require background in analog or digital filter principles in order to run it. The program is written in standard FORTRAN and is about 30 kbytes in size excluding the graphics display routines. Since it uses standard FORTRAN, it can be easily transported to minicomputer and microcomputer systems that have a FORTRAN compiler and minimal graphics capabilities. This program is available for distribution to interested institutions and laboratories.

Biometry↗

Multilingual translation techniques in the analysis of narrative medical text.

The feasibility of computer translation of scientific and medical documents is controversial. This report describes a minicomputer-based translation system (TRANSOFT) that employs word order rearrangement followed by word-for-word translation and resolution of ambiguities based on context. This translation system was applied to an entire medical textbook written in German and to short medical texts written in French, Italian, Spanish and Turkish. Results suggest the versatility of TRANSOFT for narrowly defined translation problems. As foreign language medical documents and medical records become increasingly available in computer readable form through word processing, computerized typesetting and hospital information systems, computer translation methods may provide a rapid and inexpensive means of obtaining draft translations.

Computers↗

Computerized pattern recognition used for grain counting in high resolution autoradiographs with low grain densities.

Using a video-image system coupled to a minicomputer with commercial image handling software, autoradiographic grains displayed in dark-field are counted with a fast (ca. 3.5 min for 120,000 microns 2) and reliable (false scores less than 5%) grain-recognizing FORTRAN program executed in the users memory. The grain counts are printed in a raster of adjustable size overlying a bright-field image, so that the counts can be related directly to the underlying histological structures.

Autoradiography↗

MIC-III--an integrated software package to support experiments using the radioactive microsphere technique.

MIC-III is a versatile program system to support gamma spectrometry data management and data collection for experiments using the radioactive microsphere technique. It is mainly written in PASCAL and running on a minicomputer. Hierarchical organ dissection schemes are used for unique classification and identification of samples. For each series of experiments, up to 12 different nuclides and up to 20 different organ dissection schemes can be handled simultaneously. Sample weights are collected on-line and sample radioactivities are measured automatically by gamma spectrometry under process control. The spectra with a resolution of 1022 channels are analyzed using a modified linear regression technique and a strategy to compensate for global spectrum shifts. The spectrum deconvolution algorithm was evaluated by calculating the recovery indices for known nuclide mixtures and compared to the stripping method, matrix method and a linear regression technique using window counts. Recovery values produced by MIC-III are better balanced than those of the other methods. MIC-III showed the smallest dispersion of the recovery index and exhibited least error accumulation in case of spectrum shift. MIC-III computes regional blood flow and arterio-venous shunt, and provides interfaces to customized programs or statistical software packages for further analysis. It has successfully been employed in more than 140 experiments.

Animals↗

Computer based pattern recognition of carotid arterial disease using pulsed Doppler ultrasound.

A minicomputer based system has been developed for studying carotid artery blood flow data obtained for a combined B-mode, pulsed Doppler ultrasound scanner. The goals of this work are to devise and improve techniques for estimating the extent of atherosclerosis at the carotid artery bifurcation. Features are automatically extracted from spectrum analyzed Doppler blood flow data. Five statistical pattern recognition algorithms are compared, with cross validation being used to improve the estimate of classification accuracy. A data collection protocol has been devised in which four sites are studied along each carotid arterial system. Classification of unknowns is done using a hierarchy of three decisions.

Adult↗

Local histogram information content of ultrasound B-mode echographic texture.

In the diagnostic ultrasound community, the echographic B-scan texture is an important area of investigation since it can be analyzed to characterize the histologic state of internal tissues. In the present paper, a minicomputer based system was used to digitize B-mode images and to develop a method to measure their textural information. This method is based on the concept of local information content of spatial image proposed by Lowitz (1983, 1984). It first measures the local gray-level histogram in a small square window centered on each picture element (pixel) of a digitized B-mode image. The information derived from the local histograms is then used to characterize the tissues, to partition the B-mode image into homogeneous zones of texture, to estimate to what extent a tissue is different from another, to delimit the contours of a tissue and to measure its surface. The method is illustrated on the thyroid gland but it can be applied to the study of other organs.

Computers↗

Dealing with large data sets.

Collection, storage and retrieval of large amounts of data from multiple experiments for subsequent reduction, graphing and statistical analysis need not be a burdensome task. Although turnkey systems may offer significant economies for single well-defined and repetitive tasks, they may not permit sufficient flexibility to achieve the diverse aims required by many research programs. Using popular microcomputers to run one or a few experimental subjects may confront the investigator not only with significant bookkeeping problems, but also with an allocation of labor resources to computer maintenance and support that might be better invested in research effort. By using networked minicomputers, economies of scale emerge both in data collection, transfer, reduction, and analysis, as well as in maintenance, support, and scientific effort.

Data Collection↗

Techniques for the rapid display and manipulation of 3-D biomedical data.

The use of fully interactive 3-D workstations with true real-time performance will become increasingly common as technology matures and economical commercial systems become available. This paper provides a comprehensive introduction to high speed approaches to the display and manipulation of 3-D medical objects obtained from tomographic data acquisition systems such as CT, MR, and PET. A variety of techniques are outlined including the use of software on conventional minicomputers, hardware assist devices such as array processors and programmable frame buffers, and special purpose computer architecture for dedicated high performance systems. While both algorithms and architectures are addressed, the major theme centers around the utilization of hardware-based approaches including parallel processors for the implementation of true real-time systems.

Algorithms↗

Real time control procedures for monitoring SMAC analytical performance.

A system has been developed in our Hospital Clinical Chemistry Laboratory with the aid of a minicomputer on line with SMAC. The programs are in Basic and comprise management of patient samples and of reference sera, on-line acquisition of analytical data, checks of error reporting and of abnormal result values, real time processing of quality control parameters and data transfer on floppy disk. An efficient and easy monitoring of the chemical procedures and result reliability is achieved together with instrument performance optimization.

Autoanalysis↗

Impedance cardiographic assessment of symptomatic patent ductus arteriosus.

A modified impedence cardiographic technique was developed using a tetrapolar apnea monitor and minicomputer system. Evaluation of this technique in premature infants with and without symptomatic patent ductus arteriosus indicates that the magnitude of the cardiac-related deflection in the impedance signal is useful in the assessment of ductus shunting. Since the infant under study is involved only by the attachment of two double electrodes to the thorax, continuous assessment of ductur shunting is possible without disturbing routine care.

Cardiography, Impedance↗

Endocardial mapping by simultaneous recording of endocardial electrograms during cardiac surgery for ventricular aneurysm.

A technique was developed for the simultaneous recording of 30 endocardial electrograms during cardiac surgery in patients undergoing aneurysmectomy or endocardial resection, or both, for medically intractable ventricular tachycardia. An inflatable balloon covered with 30 terminals at distances of 1.5 to 2 cm was used to record from the entire endocardial surface; a smaller silicone rubber sheet with 30 terminals at distances of 0.7 cm was used to obtain a better spatial resolution. The multielectrodes were inserted into the left ventricular cavity by way of an incision in the aneurysm. A transportable minicomputer was used for the acquisition and analysis of the signals. After initiation of ventricular tachycardia by programmed stimulation, signals of a 1.5 second period were stored and analyzed. The earliest activated terminal could be determined within 2 to 5 minutes. The technique was applied in 32 patients and proved especially useful in those patients in whom sustained tachycardia could not be evoked and in whom conventional mapping with a roving electrode would have been impossible or very time consuming. In all patients, the isochronic maps showed that the ectopic impulses originated from a rather localized area and no evidence was found for large endocardial circus movements, thereby excluding these as a mechanism underlying the tachycardia. Isochronic maps, depicting activation sequences during consecutive ectopic beats with the same QRS morphologic features, showed the same site of origin in all but six patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗