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At least 253 records · Page 14Linked to original sources

Microcomputer and microprocessor applications in cardiac pacing.

Modern adaptive dual-chamber cardiac pacemakers offer millions of combinations of noninvasively programmable operating parameters. Some pacemakers and most pacemaker programmers are microprocessor based; these "software-organized" pacemakers can undergo substantial functional redesign by noninvasive programming even after implantation. Ancillary instrumentation used in making measurements during implant and follow-up is often microcomputer based, as is experimental instrumentation used in pacing research. As electrical control of cardiac dysrhythmias becomes more sophisticated, microcomputer applications in many aspects of pacing are proliferating in research, manufacturing, and clinical practice.

Computers

Microcomputer for controlled substance record keeping.

The use of a microcomputer to maintain controlled substance inventory and record keeping is described. The system maintains perpetual inventories of the central narcotic vault and proof-of-use controlled drug records outstanding at nursing stations. The computerized system has eliminated (1) the delay previously encountered in the posting of transactions from the numeric log to perpetual inventory logs and (2) the potential addition and subtraction errors inherent in a manual system. Computerizing the controlled drug record-keeping system has saved approximately 166 minutes of labor per day, a cost savings of approximately $26. The new system also helps prevent diversion of controlled substances. The computer may also be used for other tasks while not running the controlled substance program. A microcomputer is well suited to the task of controlled-substance record-keeping functions, and the cost of the system (less than $4000) can be quickly recouped in labor savings.

California

Design of a microcomputer-based densitometer system: application to serum protein electrophoresis.

We describe how a microcomputer (Apple II Plus) can be interfaced with a commercial densitometer to provide control functions, do automated data processing, and print final reports. The amplified densitometer photodetector signal is digitized, stored, and plotted on the cathode-ray tube to provide a real-time graphical display of data acquisition. The software was designed to identify automatically the five main serum protein fractions and to compute final results. Algorithms were designed to provide medically relevant comments for most of the common abnormal protein patterns, and the comments section was designed so that it could be modified to use specific comments composed by the user. A final report, printed in duplicate, contains information such as the patient's name, identifying numbers, numerical results, normal values, medically relevant comments, and a digitized high-resolution plot of the electrophoretic pattern. The densitometer was one that already had been in use for several years; the microcomputer system, software, and interfaces cost less than $2200.

Blood Protein Electrophoresis

[Statistical analysis on 1,500 urinary calculi by using microcomputer].

In our laboratories, more than 1,500 urinary calculi have been analyzed by infrared spectroscopy. These data were statistically analyzed by microcomputer. The most frequent type was calcium oxalate combined with calcium phosphate, followed by pure calcium oxalate and magnesium ammonium phosphate combined with calcium phosphate. In particular, the composition of magnesium ammonium phosphate combined with calcium phosphate increased as compared with that four years earlier. Four years ago, we spent one month to statistically analyze 300 urinary calculi. But in this study, only sixteen days was required to analyze 1,500 urinary calculi by using a microcomputer.

Adolescent

[Electrophysiological atlas of human thalamus and adjacent structures.--Microcomputer assisted mapping of neurophysiological data and its application to stereotaxic surgery].

During stereotaxic surgery anatomical structures and their extent on trajectories were identified by neural noise (field potential) obtained by semi-microelectrode technique. Locations of anatomical structures (the white mater, caudate nucleus, thalamus, subthalamic field and nuclei in the subthalamic field) were fed into microcomputer (NEC PC-8001) as 3 dimensional correlates and stored in minifloppy disc system (NEC PC-8031). Data with satisfactory recordings from 48 trajectories from 30 patients (18 parkinsonism, 5 central pain, 7 others) entered this study. Microcomputer was so programmed that locations of the trajectories and electrophysiologically identified anatomical structures at that location in various coronal, sagittal and horizontal planes were displayed. Accumulation of this display from various groups of patients automatically created electrophysiological atlas. For comparison of thus created electrophysiological atlas with anatomical atlas display was made on various sections of the Schaltenbrand and Bailey's Atlas which were also stored in the mimifloppy disc system. Electrophysiological topography of the thalamus and adjacent structures was reasonably similar to anatomical topography with minor, but significant individual variations. In most cases the ventral border of the thalamus was located in the close vicinity of CA-CP line, however, in some cases the thalamus was located deep into the subthalamic field. This was thought to be due to the difficulty in identifying the ventral border of the thalamus by this technique and in such occasions other neurophysiological method for identifying the ventral border of the thalamus, i.e., thalamocortical evoked potential and other stimulation technique, were necessary. Medial aspect of the V. im. nucleus emitted neural noise of different characteristics which in current program was recognized as the subthalamic field. This implies that the medial and lateral aspects of the V. im. nucleus are cytoarchitecturally different and that it is possible to differentiate the medial and lateral aspects of the V. im. nucleus by this technique. The lateral thalamic border, i.e., thalamocapsular border, also showed relatively wide range of individual variations. When various parameters including age, sex, diagnosis and width of the 3rd ventricles were examined for possible cause of these variations, a tendency was noted that the thalamocapsular border was medially placed when the width of the 3rd ventricle was small. In this system it is possible to display sequentially electrophysiologically identified structures along any trajectory. This display method, which was called "tract study," was very usefull for comprehensive understanding of location of trajectory in relation to individually varying anatomical structures...

Adolescent

The microcomputer-based color image analyzer and its application to histochemistry.

For quantification of histochemical reactions, color image analysis, as well as cytophotometry, is important. However, the extremely large amount of information, usually more than one million bits per image, involved in one microscopic picture of a colored histochemical specimen, when digitalized, has inhibited attempts to develop a more convenient system of color image analysis. Recent advances in microcomputer technology have now made it possible to build, at a reasonable cost, an intelligent color terminal equipped with array-processing hardware, a sufficiently large video random-access memory to represent 4096 colors in each pixel, and packages of machine language subroutines called "macro-commands" in the form of read-only memory that can process color images within a few seconds. This intelligent terminal can easily be controlled by a small personal computer via an IEEE-488 interface bus. The digitalized color image can be stored in and retrieved from a floppy disk. As the macro-commands in this system are controlled by BASIC program through CALLS with parameters, it is highly flexible and adapts readily to the varied needs of histochemists. Reported on herein will be the instrumentation of the microcomputer-based color image analyzer and a few examples of applications of this system to histochemistry: color intensification of cytochemical reactions, quantification of enzyme (e.g., horseradish peroxidase) reaction products, periodic acid-Schiff staining, collagen fibers visualized by Azan-Mallory stain, etc. Possible future applications of this color image analyzer will also be discussed.

Animals

Surgical pathology reports with a portable microcomputer.

A microcomputer reporting system for gross and microscopic surgical pathology is simple and inexpensive, reduces the need for clerical personnel, and saves the pathologist's time in the preparation of reports. Gross descriptions are performatted. A dictionary of microscopic diagnoses is constructed and stored on disks. The diagnosis to be used for a case is selected by a pathologist by number. It is called to a video screen from disk storage by entering the number on the microcomputer keyboard. The diagnosis is edited or expanded for an individual patient while it is on the screen and is printed after changes are made. Each diagnosis contains preentered classification, coding, and filing information, as well as format, medical terminology, and spelling. The system has rapid retrieval and search capability and may be used for patients awaiting frozen-section diagnosis. The system requires fewer clerical personnel in surgical pathology than with free-form reporting.

Computers

An interactive graphic database microcomputer for clinical control in data intensive therapies.

Experiments showed a small computer could improve access to large concentrations of clinical data in renal dialysis and transplantation and enhance the clinical feedback loop which controls substitute renal function. Interactive access adds a sub-loop which allows close adaptation to clinical use. Prototype software was transferred to an LSI-11 microcomputer with 20 Mbyte cartridge discs, multiple remote VDUs and video graphic displays and printer-plotter. Data capture is both manual and by automatic transfer from laboratory computers. Push-button interaction displays clusters of data, including computed functions, as graphs and tables on variable time scales. programmed scans generate data-base analyses. The system reconfigures for individual sites. The microcomputer version has run routinely for a year and proved a practical tool at acceptable cost. Down-time has been small but strongly resented by medical and nursing staff. The system can accommodate 750 patients, but has also been 'stretched' for an oncology laboratory and configured for other specialities.

Computers

Microcomputer as patient educator.

A computer-assisted lesson on general drug knowledge as a patient education tool is described. A drug I.Q. quiz is one of seven microcomputer lessons available to patients in the waiting room of an ambulatory-care clinic. The drug quiz consists of 19 multiple-choice and six true or false questions. After each question, the computer responds with a brief paragraph keyed to the answer selected by the user. If the answer for a multiple-choice question is incorrect, the user can reanswer the question before proceeding. At the end of the lesson, a score is graphically displayed and the user is asked to evaluate the lesson. The computer stores the total number of lessons completed, total scores, number of times each question was answered incorrectly on first and second attempts, number of times each question was answered a second time, and each user's responses to the quiz and evaluation questions. Based on 313 completions of the drug quiz from September 1981 through May 1982, 86% of the users stated that they learned at least something useful, and 72% liked the quiz. The mean (+/- S.D.) number of correct answers on the first attempt was 16 +/- 5; scores improved by an average of 2.5 +/- 2 by reanswering questions. Of 2421 multiple-choice questions answered incorrectly, 62% were reanswered. Of these second attempts, 52% were correct. Item validity scores indicated that the drug quiz serves as a realistic appraisal of drug knowledge. The microcomputer can be an effective medium for patient education.

Computers

Modular design of microcomputer-based medical instruments.

A modular design approach is effective for developing compact microcomputer-based medical instruments. Each instrument consists of two modules: a microcomputer instrument module that provides data conversion and computing functions and a characteristic module that does analog signal conditioning and includes all interfaces to the environment. The five instruments summarized here are: (a) a portable, battery-operated arrhythmia monitor for ambulatory patients; (b) a physician's computer for remote telephone communication with the portable monitor; (c) a battery-powered arrhythmia monitor/recorder for the operating room; (d) a portable, battery-operated biofeedback device for speech therapy; and (e) a neuromuscular blockade monitor for the operating room.

Computers

[The use of microcomputers in the processing of complex hemodynamic data].

The use of a low-cost microcomputer in the clinical study of left ventricular diastolic function is described. Both left ventricular filling and compliance were studied by means of the simultaneous recording of left ventricular pressure and an echocardiogram displaying ventricular dimensions. A program was written to calculate ventricular volume every 40 msec and a volume-time diagram was obtained. The raw curve was smoothed with a second degree polinomial. The rate of change of ventricular volume (dV/dt) was obtained. Simultaneous left ventricular volume and pressure were plotted. The diastolic, exponential portion of the pressure-volume loop was used to calculate an index of ventricular stiffness at zero volume. It is concluded that a simple microcomputer, when conveniently programed, is able to perform the time-consuming mathematical operations involved in the clinical assessment of left ventricular diastolic function.

Cardiac Volume

The impact of response options and location in a microcomputer interview on drinking drivers' alcohol use self-reports.

The influence of response options for and location of frequency of alcohol use items in a self-administered microcomputer interview were evaluated in a randomized, experimental study of 296 clients at a west coast treatment site for drinking drivers. Respondents were asked about their frequency of alcohol use in the last 7 days, 30 days, 90 days, and 180 days with three methodological factors randomized: (1) how quantitative the response options were; (2) order of presentation of close-ended response options; and (3) relative placement of alcohol use items in the questionnaire. Results indicate that these methodological factors had minimal influence on self-reports of the frequency of alcohol use. Only two statistically significant effects out of 44 possible were observed. The findings of this study suggest that frequency of alcohol use reports by drinking drivers yield similar information for a range of different response formats and location of the items in a microcomputer interview.

Adult

Microcomputer programs for complex epidemiologic procedures. I. Computation of adjusted rates.

In epidemiological cohort studies one measure of association based directly on incidence or mortality rates is the excess rate. This measure is defined as the excess in these rates between two groups with different exposure experience. At times the computation of these excess rates separately for each of the categories of a risk factor is crucial, as with these rates we can then determine whether the factor exerts a dose-response effect that may implicate a causal relation. Recently an indirect method of standardization has been reported, which computes the excess rates for a factor that are adjusted for the confounding effects of several other factors. The method involves a complex iterative procedure that cannot be carried out easily without the aid of a computer. The objective of this communication is to make available a microcomputer program that has been written to implement this laborious computation. In this pedagogic note the adjustment method is described and the application of the microcomputer program is illustrated.

Epidemiologic Methods

A microcomputer-based package for determination of regional and global cardiac function and coronary hemodynamics.

A multichannel data acquisition package for reduction of systemic and coronary hemodynamic data that utilizes a personal microcomputer is described. The system provides a printout of heart rate, maximal rate of left ventricular pressure development (+dP/dt), maximal rate of ventricular relaxation (-dP/dt), absolute and normalized myocardial segment lengths, the degree of shortening of the segment over the cardiac cycle, systolic, diastolic, and mean coronary blood flow velocities, left ventricular systolic and end diastolic pressures, and systolic, diastolic, and mean aortic blood pressure from six channels of input data. Obtained values are precisely linked to the cardiac cycle. To illustrate the output of this system, data obtained by reading strip-chart records are compared to microcomputer-derived values in conscious, instrumented dogs.

Animals

An application of a microcomputer compiler program to multiple logistic regression analysis.

Microcomputer programs for multiple logistic regression analysis were written in BASIC language to determine the usefulness of microcomputers for multivariate analysis, which is an important method in epidemiological studies. The program, carried out by an interpreter system, required a comparatively long computing time for a small amount of data. For example, it took approximately thirty minutes to compute the data of 6 independent variables and 63 matched sets of case and controls (1:4). The majority of the calculation time was spent computing a matrix. The matrix computation time increased cumulatively in proportion to additions in the number of subjects, and increased exponentially with the number of variables. A BASIC compiler was utilized for the program of multiple logistic regression analysis. The compiled program carried out the same computations as above, but within 4 minutes. Therefore, it is evident that a compiler can be an extremely convenient tool for computing multivariate analysis. The two programs produced here were also easily linked with spreadsheet packages to enter data.

Computers

A microcomputer-based data acquisition and analysis system for CO2 rebreathing studies.

A real-time microcomputer-based data acquisition and analysis system has been developed to automate the measurement of the ventilatory response to CO2 by the rebreathing method. Previous systems acquire the data on-line and then analyze and display the results off-line. The system described here performs all processing on-line and displays experimental results in real-time. The results of 5 min of data acquisition are available for display only 1.5 sec after completion of the experiment. Immediate interpretation of the results of each experiment enable a series of related studies to be performed on the same patient in a short time period. The microcomputer is Digital Equipment Corporation's LSI-11, a low cost 16 bit machine with the basic instruction set of a PDP-11/40. The system has 16 kbytes of memory, a CRT for data display, and a paper tape reader for program loading. Due to the time constraints of real-time processing and the memory constraints of a small system, the software is written entirely in assembler language. The software includes routines for numeric and character input, line and graphical output, linear curve fitting, start of rise detection and floating point computations.

Carbon Dioxide

Diagnosing human malformation patterns with a microcomputer: evaluation of two different algorithms.

SYNDROC, a microcomputer-aided differential diagnostic approach to human malformation patterns, is based on a pseudo-Bayesian algorithm. This means that, for each sign, the frequency of this sign in the general population, its frequency in a particular syndrome, and the frequency of that particular syndrome have to be determined. These parameters are easy to find in common syndromes but tend to be difficult for rare or isolated cases. Thus, we implemented a new algorithm called the "descriptive algorithm," which defines a diagnosis by a set of anomalies all having the same weight. To test this algorithm, we analyzed 100 cases representing 100 different syndromes out of the register of the Division of Medical Genetics, Children's Hospital and Medical Center, University of Washington. The descriptive algorithm was allowed to give 3 sets of diagnoses. In 91% of the cases, this algorithm proposed the correct diagnosis (54% in the first window, 28% in the second window, and 9% in the third window). The number of diagnoses proposed was 18.78 +/- 16.57. The same cases were analyzed with the pseudo-Bayesian algorithm. The concordant diagnosis was proposed in 92% of the cases (55% at the top place, 11% at the second place, and 26% at the third place or beyond). The number of diagnoses submitted was 13.5 +/- 11.04. The combined algorithm gave the correct diagnosis in 96% of the cases. This study shows that the descriptive algorithm is as accurate as the pseudo-Bayesian algorithm in diagnosing malformation patterns, but this level is accompanied by an increased number of proposed diagnoses.

Abnormalities, Multiple

An integrated microcomputer system to maintain a genetic register for Huntington disease.

A microcomputer program has been designed to maintain a large data base for Huntington disease. This program facilitates such data manipulation as adding, altering, retrieving, deleting, and printing pedigrees. The program is self-contained and has a risk-calculating routine built in which automatically provides both the Mendelian and age-modified risks. This package is capable of printing the pedigrees on a simple printer or, alternatively, creates an output-file which can be used with a dedicated plotting program for drawing the pedigrees and their data on a plotter. The program has a routine which can provide a series of statistical data from the register including age-of-onset, diagnosis, death, and other useful information.

Computers