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A laboratory computer system in described which will rapidly generate gray-scale maps showing the distribution of measures derived from the electrical activity of the brain, such as the electroencephalogram (EEG) or other biological measures. The system allows flexible description of electrode number and placement, mapping onto any shaped space and rapid generation of maps by integration with the data collection software.

A general computer program, of interest to neurobiologists, for comparison of uncorrelated power spectra is presented. The program, ALPHAF, is written in Fortran V language and is easily compiled and executed in any computer with a Fortran software package. The purpose of the program is to read power spectral density (PSD) values into a computer from digital tape and then perform the following functions: (1) compute and report power; (2) compute and report averages of the computed power values over selected frequency bands and (3) compute and report statistical standardised normal distributions for a frequency spectrum of interest. The standardised normal distribution statistic is derived by using equation 7.20, page 250 of Random data: Analysis and measurement procedures (Bendat and Piersol, 1971).

Point-by-point calculation of the mean transit time based on gamma fit was used to analyze brain perfusion studies in a vertex view. The algorithm and preliminary results in normal brain and in different stages of cerebral perfusion abnormality (ischemia, stroke, migraine, tumor, abscess) are demonstrated. In contrast to the traditional methods using fixed, a priori defined regions of interest this type of mapping of the relative regional cerebral perfusion shows more clearly the irregular outlines of the disturbance. Right to left activity ratios in the arterial part of the time-activity curves showed significant correlation with the mean transit time ratios (Qt = 1.185 - 0.192 Qa, n = 38, r = 0.716, P less than 0.001).

We have designed and built a database management system, the computer assisted patient evaluation (CAPE) system, for use in patient management, research, and administration in our anesthesia practice. An important part of the system is the use of specially designed forms on which anesthesiologists record patient histories and management information during the course of patient care. The forms provide means for convenient and complete record keeping, as well as for direct computerization. We demonstrate the flexibility and utility of the CAPE system by presenting a series of examples of its use. These include development and implementation of a preoperative screening program to identify patients at high risk of postoperative respiratory complications; a study of anesthesia technique and outcome; auditing for quality of care; and utilization review of respiratory therapy.

From replies to a postal questionnaire used in a radioactive iodine follow-up scheme patients had to be classified as either "suspected hypothyroid" or "euthyroid." A comparisons has been made of the effectiveness of published statistical techniques in making this classification. Two main conclusions emerged. Firstly, all except one of the methods identified an acceptable proportion of the hypothyroid patients, and, secondly, the results given by these methods were remarkably similar. Thus the simplest, which required only a count of the number of symptoms present, was selected for use.

A computer-aided graphical analysis system is presented which can be used to quantify several types of information from micrographs of cross-sectioned peripheral nerves. A simple input consisting of eight points, corresponding to two diameters of each axon and two for each axon plus myelin, is used to compute statistical and numerical estimates of these diameters, the myelin thickness being expressed as a function of axon diameter, and both the spatial position and distribution of nerve fibres within the bundle. The computer programs presented and summarized here describe the procedure for digitizing the input data and the subsequent computations for editing and analysis. The general applicability of this approach for automated analyses of other anatomical areas is also presented.

The analysis of data generated on a flow cytometer (FCM) is often performed on a computer obtained especially for dedicated use with the flow cytometer. This computer component can be expensive and also presents the FCM user with the added burden of mastering specialized programming language or of accepting the secret analytical processes of protected proprietary program routines. We believe that the evolution of more accurate and efficient FCM analyses that have the power to consider complex signal distributions can be assisted by the availability of analysis programs written in languages common to many users. DNA analysis routines written for a relatively inexpensive microcomputer (IBM PC/XT) in Basic and Pascal are described here. The routines can automatically process multiple FCM data files and can provide high-resolution graphic hardcopy. A foreground/background utilization is also described that allows the computer to be available for other uses in the laboratory.

Experiences in a two years application of electronic data processing in medical routine microbiology are reported. Optical mark reader forms serve as request forms as well as workprotocol. On the left two thirds of these forms (Fig. 1 and 2) the patients data including clinical statements, and the kind of specimen to be investigated (sputum, smear etc.) as well as results not essential for the printout of laboratory reports are filled in. On the right third of the optical mark reader form, in which area the Bell & Howell document reader can read pencil marks, the patients identification number, the tests requested and all results are marked right at the work bench. As shown in the flow diagram (Fig. 3) after completion of the investigation the date on the mark reader forms are read mechanically and the test results are printed (Fig. 5) by means of the computer. In addition, the data processing system, which proved to be very flexible, performs all necessary types of administrative work as filing of laboratory data in a coded form on cards for permanent storage (Fig. 7) statistics and the printout of bills (Fig. 6). The processing of routine microbiology date is achieved by a Siemens DVA 404/3 (64 kbt) connected for magnetic disc device (2993 Mio bytes), and a line printer (60,000 lines per hour) and dialog display monitors, which are used simultaneously for the on line and off line handling of all the data in clinical chemistry-, serology- and hematology-departments of the same institute.

A system of digital measuring of the cardiac action potential was constructed in order to measure quickly and accurately the resting potential or maximum diastolic potential, overshoot potential, amplitude, time for 50% repolarization and time for 90% repolarization. This system consists of a dual-beam oscilloscope, a digital voltage meter, a digital interval meter and a simple circuit constructed by operational amplifiers. The measurement of the action potential was achieved by tracing only the resting potential or the maximum diastolic potential and the crest of the action potential on the oscilloscope using another beam. The time for measurement is usually 10-15 sec and errors in measurement were considered to be negligible. This system is considered to be useful for digital measurement of the action potential of various cardiac tissues. This system was applied for observation of effects of bufetolol, an adrenergic beta-receptor blocking drug on the action potential of the dog Purkinje fibres. Bufetolol (10(-5) M) caused a slight depolarization of the maximum diastolic potential, decreased overshoot potential, amplitude and maximum rate of rise, and shortened the time for 50% repolarization of the action potential. Bufetolol (10(-4) M) additionally prolonged the time for 90% repolarization.

Digital subtraction angiography (DSA) with intravenous contrast injection was performed on 500 consecutive adult patients and evaluated for image quality of the carotid artery bifurcations. Diagnostic quality examinations were obtained in 974 common, 925 internal, and 904 external carotid artery segments. Sixty-two patients had standard carotid arteriography around the same time as DSA. Agreement of standard arteriograms with diagnostic quality DSA examinations was noted in 97 of 98 common, 94 of 95 internal, and 79 of 91 external carotid artery segments. All cases of complete carotid occlusion (14 of 14) were correctly interpreted by DSA. To identify a population with clinically significant stenosis, a 60% or greater reduction in diameter of the internal carotid was defined as a positive examination. Applying this criterion, the sensitivity, specificity, and accuracy of DSA as compared with standard arteriography was about 94%.

The most common types of nucleotide sequence data analyses and handling can be done more conveniently and inexpensively on microcomputers than on large time-sharing systems. We present a package of computer programs for the analysis of DNA and RNA sequence data which overcomes many of the limitations imposed by microcomputers, while offering most of the features of programs commonly available on large computers, including sequence numbering and translation, restriction site and homology searches with dot-matrix plots, nucleotide distribution analysis, and graphic display of data. Most of the programs were written in Standard Pascal (on an Apple II computer) to facilitate portability to other micro-, mini-, and and mainframe computers.

Our target is to build a flexible computerized system based on an informational study of the clinical laboratory, which would leave the laboratory staff free to use equipment or modules from different manufacturers interchangeably. This applies to hardware and software. To fulfil this objective, it is necessary that automatic analyzers, microcomputers and minicomputers, have built-in standardized hardware and software interfaces. Technical specifications of the IEEE 488 standardized interface, recommended by the authors, are presented here; this interface is already widely used in instrument interfacing with low-cost microcomputers are minicomputers but has not yet been used for clinical laboratory automatic analyzers. A design for a flexible laboratory based on this interface is presented, with a discussion of the feasibility of such a project.

A model-independent program for pharmacokinetic analyses based on statistical moment theory is presented and demonstrated. The program uses an inexpensive and portable TI-59; a PC-100A printer adds convenience but is optional. The program may be used in analysis of blood, serum, or plasma concentration vs. time curves originating from iv, im, po, sl, or sc administration. Drug input can be zero or first order; both single-dose and multiple-dose steady-state conditions can be evaluated. A comparison between results generated using moment analysis and traditional two-compartment nonlinear regression showed excellent agreement.

Multiparameter flow cytometric measurements are of growing interest in the study of complex features of biological cells. With state of the art instrumentation, three-parameter (3-P) data handling is relatively complicated and time consuming and the display methods are not satisfactory. As an alternative, an interactive 3-P analyzing module, Cytomic 123 is described, which displays 3-P fields during and immediately after data uptake in the form of a cubic array of 32,768 channels. The fields can be randomly rotated by hardware and software. The event frequencies in the field are primarily visualized by brightness modulation of the display dots. Additionally, the display of the field may be confined to user selected ranges of event frequencies, which may also be superposed to mixed frequency displays. A set of preprogrammed functions is available for the following tasks: (a) uptake of 3-P histograms combined with on-line control of the transducer pulses, (b) automatic uptake of a series of 2-P time correlated histograms in the cube, (c) generation and numerical evaluation of sections and projections of cube histograms, (d) interactive generation and evaluation of spatial subfields for integration, or as sorting matrix by successive erosion of section planes, or reprojection of projection windows, and (e) isometric display of sections and projections and exchange of data sets with other Cytomic modules or other data systems, especially the Cytomic 12 module, whose 2-P capabilities can be used. The module is built with low cost Z80 microprocessor eurocards. A standard oscilloscope serves as a display unit.

A general procedure for fitting compartments models of alveolar ventilation-perfusion ratio (VA/Q) distribution to inert gas elimination data is described. The method can be applied to any model consisting of a number of compartments ventilated and perfused in parallel, each compartment of the model having a fixed predetermined VA/Q ratio. The number of compartments and their VA/Q ratios required for adequately fitting real data have been examined. A 13-compartment model consisting of a shunt, a dead space, and 11 compartments equally spaced on a logarithmic scale from VA/Q of 0.01 to 100 was found to be suitable. The fitting procedure and the 13-compartment model form the basis of a method of analysis of inert gas elimination data. Essentially the method consists of calculating a sample of 30 distributions compatible with the data analyzed taking into account experimental errors in the inert gas measurements. From this sample, the averages and standard deviations of the flows to 13 zones on the VA/Q scale are estimated. The averages are estimates of the true flows to these zones, and the standard deviations give an indication of the range of flows compatible with the data. The method has some advantages over both the enforced-smoothing approach and the Monte Carlo linear programming scheme of Evans and Wagner (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 42: 889-898, 1977).

Three-dimensional surface images can be reconstructed from CT scans. These are particularly useful in the study and management of patients with congenital and acquired craniofacial deformities. The principles of 3-D reformation, the production of the surface images, and recent advances in modification of these images for specific clinical needs are presented.

An interactive computer graphic system has been developed for 3-D reconstruction of stained serial sections. The system has been used for 3-D reconstruction of portions of mouse lung containing melanoma nodules. A stereoscopic color picture of a wire model of the reconstructed object is produced. The volume, surface area, and sphericity index of structures such as tumor nodules can be computed.

The two-dimensional perspective display of three-dimensional patient contour data is useful in radiotherapy treatment planning as it provides a comprehensive view of the relative positions of patient internal (organ and target) and external contours. The advent of minicomputers and video display systems has made possible the integration of such display techniques into the treatment planning routine. This paper describes and gives an example of the methods we have found useful in producing perspective displays of patient contour data. Included is a solution to the problem of removing hidden line segments from the displayed image.

The presented software package fulfills the need for processing serial sections with a microcomputer configuration, enabling three-dimensional reconstruction with hidden line removal. The language used is an interpreted BASIC-dialect (HPL). The input is performed via an interactive program. The object can be rotated in space. The Hidden Line algorithm does not depend upon a raster technique. Points of intersection of successive contours are calculated and inserted, thus providing drawings of high resolution and quality. The handling time can be said to be short, especially when considering the capacities of the microcomputer configuration used.

Personal computers are quickly becoming items of everyday use. More physicians' offices are using computers for billing and patients' records. Others have purchased computers for their word processing capabilities. These computers can be used for archives of medical case records or to collect and collate data for clinical research. This article focuses on how we use a personal computer for organization and management of clinical research projects. Included is a description of how we organize a research project, gather data, write computer programs, enter data into the computer, and generate and display reports. The use of a template program and a personal computer permits creation of individual programs without the aid of a professional programmer. When a single data-management program is used, five or six research projects can be carried out at a cost comparable to that of one project using a large computer and professional programmers.

Practical applications for using computers in everyday medical practice have not kept pace with the technical developments that now make this tool available to the pediatric practitioner. A modular approach to user-developed applications software is presented as a model for computerizing the pediatric office. Benefits have included lower cost, greater data reliability and validity, standardization of office and medical procedures, and automation of jobs formerly requiring much personnel time. Some patient services have improved, and other new services have become possible, through the application of computer software designed in accordance with our practice philosophy.

In order to complete the logistics of the unit cytapheresis, we have developed a decision helping system which rests upon the computer management of -196 degrees C cryopreserved HLA type platelets. The hardware used is a micro-computer equipped with two floppy disks and a printer. Two files have been created: namely "Product" and "Patient". Data relating to 800 platelet concentrates may be recorded on a floppy disk. The software which has been developed has several functions: 1 - The input of the parameters of a HLA type concentrate with the possibility of reservation for the given recipient; 2 - The print out of the bank's stock; 3 - The selection and the reservation of HLA matched platelets according to the recipient; 4 - The print out of concentrates allocated to each patient, it is possible to thaw out chosen platelet concentrate and a thawing report is printed out, thus enabling one to locate the concentrate in the bank. Thanks to this "aid in decision making", the management of - 196 degrees C cryopreserved HLA type platelets may be carried out. The proposed software allows an one line answer for any emergency transfusion case. Considering the recipient HLA typing the suitable best match platelet concentrates are instantly transfused or save.

The development of the radiologic technique, digital subtraction angiography (DSA), has substantial importance in studying the uveal vasculature and its orbital blood supply. After rapid intravenous injection of commercially available contrast material, images of the orbital and uveal vessels of rabbits, cats, and the nonhuman primate can be observed. Advantages and limitations of this new technique for visualization of uveal and orbital vasculature were evaluated in serial experimental animal studies. Future potential clinical applications are discussed.

For closed sequential binomial sampling plans (including plans for multistage sampling), the probability of reaching each terminal point is calculated. These probabilities are cumulated from "each side" of the plan. Thus, the power function obtainable by defining any (reasonable) acceptance region can be studied. Corresponding to a given outcome of the trial confidence limits can be calculated by an auxiliary program.

This article discusses the design and implementation of a program well suited to integrating experimental or simulated data obtained at fixed intervals. The program uses Simpson's method and produces substantially better accuracy than trapezoidal rule integration at little extra computational cost. It accepts command line specification of integration parameters (step size and/or number) and source files. Multiple source files and integration parameters can be specified at runtime. Output can be displayed on the console or redirected to an ASCII file.

A procedure employed for input of low-frequency physiological information coming via several channels in a digital computer, model M-220A has been worked out. The operations are effected through the application of standard equipment with the use of routine communication channels to the computer. Particular attention is attached to the storage of the input information in the permanent memory of the machine for further synchronous analysis of physiological indices. The procedure may find use in analyzing materials covering a wide range of medico-biological experiments.

A computer program for the analysis of 51Cr labelled red cell survival data was used in 84 patients and 8 normal subjects to estimate the parameters of 7 competing models derived from different hypotheses of the red cell destruction process. The purpose was to establish the optimal complexity of a red cell survival model to be used. Senescence or random destruction were the most common identified patterns of red cell death (79% of the cases). Models assuming different levels of death probability according to the age of cells, or 2 populations of cells with different death probabilities, were selected in 21% of the cases. These latter patients were characterized by the lowest values of MRCL. The conclusion of the work was that an automatic procedure for selecting the best model of red cell destruction is necessary when information concerning the mechanism of red cell death is required. For the more practical aim of obtaining an accurate measurement of the MRCL, the minimal set of competing models should account of at least 2 different populations of cells in addition to the random or senescence destruction models.