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Automated nerve fibre size and myelin sheath measurement using microcomputer-based digital image analysis: theory, method and results.

In either clinical or research settings, manual measurement and counting of myelinated fibres in peripheral nerve is tedious and error-prone, yet fully automatic computerized counting and measuring of fibres fails to count small fibres and eliminate extraneous profiles in the tissue. This article describes an operator-interactive, semiautomated method for quantification of myelinated nerve fibre data using commercially available hardware and software on an inexpensive, yet full-featured image analysis system based on a microcomputer. Software macros automate the acquisition of data from the microscope images and the production of numerical and graphic data, with output to either paper hardcopy or 35 mm colour slides. User control is retained for dynamic thresholding, binary image creation and elimination of artifacts. In addition to generating the classic histogram showing the size distribution of nerve fibres, the thickness and variability of myelin sheaths are also graphically depicted. The method is based on measurement of myelin area and total perimeter, with calculation of equivalent circles and diameters for both axon and nerve fibre. Measured fibre sizes are thus somewhat larger than those resulting from manual methods using the minor diameter of an oval profile, or mean diameter of crenated or irregular profiles. The method allows the rapid measurement and counting of numbers of fibres previously impossible to assess manually, or using digitizing tablets. By increasing the speed and accuracy of data acquisition and processing using widely available microcomputers, the method may allow a better description of peripheral nerve changes in research and clinical settings.

Analog-Digital Conversion

A system for quantitative analysis of associative learning. Part 2. Real-time software for MS-DOS microcomputers.

Microcomputer software was designed and used to control the timing and delivery of sensory stimuli and to acquire and analyze behavioral data during classical conditioning experiments. The software package runs under DOS 4.x through 6.x (earlier versions run under DOS 3.x) on PC AT-compatible microcomputers coupled with appropriate interface hardware (see Thompson et al., 1994). The software controls timed delivery of up to 8 conditional stimuli. It can collect behavioral data from 2 subjects simultaneously performing the same task (e.g., eyeblink responses) or from a single subject performing 2 different tasks (e.g., both eyeblink and conditional discrimination tasks), permitting its use in a number of experimental paradigms. Digital timing signals are adjustable for different stimulus output systems. Behavior is continuously monitored onscreen, ensuring consistent measurement across trials. Real-time performance measures of the presence or absence of conditioned responses allow coordination with external events (e.g., serum sampling, drug delivery, or single-unit recording). Quantitative measures are generated both for each trial and for complete sessions. Records are stored to disk and can be printed or merged for statistical analyses. Data can be archived on standard media, and internal software utilities translate files for export to PC and Macintosh programs. This system and the hardware described in the preceding paper combine ease of use with extremely replicable behavioral measurements across trials, sessions subjects, cohorts, and studies.

Animals

Concurrent clinical review: using microcomputer-based DRG-software.

Since the introduction of the Prospective Payment System based on Diagnosis Related Groups (DRGs) in the U.S.A., important information technologies are arising. We discuss how Professional Review Organizations, (PROS) are forcing a better control of appropriateness and quality of medical care. Hospitals should have the internal capabilities to perform, at least, the same reviews as performed by the PROs. Concurrent Clinical Review Systems based on DRGs are a special type of information technology that take place during and even before patient hospitalization, therefore allowing an 'on line' monitoring information. Low-cost microcomputers are playing a major role in the popularization of this technology. 'Clinical Review System' is a microcomputer-based software that renders easy and feasible and otherwise complex task. An effort should be made in order to adapt the philosophy underlying this or other similar software to the European needs.

Computers

Real-time acquisition and analysis of cardiac action potentials and twitches using a programmable digitizer and a microcomputer.

Action potentials and single twitches from papillary muscles were acquired and analyzed in real-time using a programmable digitizer and a microcomputer. This combination provides greater control and flexibility during data acquisition than standard analog-to-digital converters. The present system was designed to facilitate evaluation of experimental drugs. However, the combination of a programmable digitizer and a laboratory microcomputer can be applied to a variety of applications in biomedical research.

Action Potentials

BACTID: a microcomputer implementation of a PASCAL program for bacterial identification based on Bayesean probability.

A computer program (BACTID) is described which enables the identification of bacteria based on a priori data and Bayesean probability testing. The program is not limited to a specific format, has a short execution time, can be easily applied to a variety of situations, and can be run on almost any microcomputer system operating under either 8-bit CP/M or 16-bit MS-DOS or PC-DOS. Additionally, BACTID is not limited to one type of computer (hardware independent); is not limited by size of the computer's random access memory (RAM independent); can recognize various database matrices (format independent); is able to compensate for missing data; and allows for various methods of data entry. The efficacy of the program was checked against a commercially available test system and a 99.34% agreement was obtained. Also, the execution time for a 46 x 21 data matrix was as little as 3.5 seconds. These results show that microcomputer identification programs not only are viable alternatives to code-book registers, but also offer flexibility which is not found in commercial systems.

Bacteria

Microcomputer-assisted univariate survival data analysis using Kaplan-Meier life table estimators.

We describe a microcomputer program (KMSURV) for exploratory univariate statistical analysis of survival data which is directly applicable to the evaluation of clinical trials and to retrospective epidemiological studies of hospital registry-based data. The program calculates life-table-like information based on Kaplan-Meier's product-limit estimators of the survivorship function S(t) and provides summary measures of average survival times. In addition, two non-parametric tests for the comparison of survival distributions are performed. A report-quality, high resolution plot of the S(t) estimates for all groups being compared complements each set of analyses. KMSURV is not a simple adaptation of a mainframe statistical analysis package and, thus, it utilizes efficiently the interactive environment which is inherent in microcomputing.

Actuarial Analysis

RIAPC: a microcomputer program for the analysis of radioimmunoassay data.

A microcomputer program for analysis of radioimmunoassays has been developed for use on microcomputers which operate under MS-DOS system software. The program messages are contained in an ASCII text file in French, English, and Spanish and can be modified by the user. The parameters and data can be entered manually into screen tables, or read from external files. An unweighted log/logit transformation is used for regression analysis of the standard curve. Provision is made for correction of the sample measurements for procedural losses (recovery). All results are written to an ASCII text file which can printed and/or reduced in order to pass the sample concentrations to other programs.

Humans

Prevalence survey of infection in a Hong Kong hospital using a standard protocol and microcomputer data analysis.

A 1-day prevalence survey of hospital infection was performed in June 1985 at a new general teaching hospital in Hong Kong. The 1980 British national survey protocol was used, and the results were analysed by microcomputer. The major part of the survey was carried out by nine people over a period of 3 days and was completed within 6 weeks. The rate of hospital-acquired infection was 8.9% and of community-acquired infection was 16.5%. Antibiotics were mainly used in infected patients. The British protocol is suitable for Hong Kong hospitals, and with microcomputer data analysis such surveys can be completed quickly and accurately even with limited resources.

Adolescent

A microcomputer aided control system for visual tracking task of monkey.

A microcomputer aided control system for visual tracking tasks is described. A video monitor displays positions of target and pointer. In a handle task, the horizontal position of a pointer is coupled to the angular position of a manipulandum. The task involves alignment and maintenance of a pointer on the target. In a bar press task, the pointer moves incrementally after each preset number of bar presses. A microcomputer and video monitor afford system flexibility, while a panel of manual switches permits the setting up of a variety of experimental conditions without extensive keyboard inputs and has the added advantage of constant display of task details. The program is written in assembly language to meet requirements for program control speed and allow timing measurement in msec. This system may be useful in the behavioral study of physiological and neurophysiological functions.

Animals

Applications of an inexpensive microcomputer for the general radiologist.

Computer programs of interest to the general radiologist have been written by the author and others for an inexpensive microcomputer. Most of these programs are in the public domain and include: computer-assisted diagnosis; computer-assisted medical education; Bayesian analysis, general statistical analysis; word processing; and radiographic image analysis. Previously, computerized functions such as these have been limited to those with access to a large institutional computer. Due to the general availability of inexpensive microcomputers, the average radiologist or group can now afford the many benefits a computer can add to the practice of radiology.

Computer-Assisted Instruction

A microcomputer-based whole-body counter for personnel routine monitoring.

The paper describes a cost-effective NaI(Tl) whole-body counter developed for routine examinations of worker intakes at an isotope production facility. Signal processing, data analysis and system operation are microcomputer-controlled for minimum human interactions. The pulse height analyzer is developed as an microcomputer add-on card for easy manipulation. The scheme for radionuclide analysis is aimed for fast running according to a knowledge base established from background samples and phantom experiments in conjunction with a multivariate regression analysis. Long-term stability and calibration with standards and in vivo measurements are reported.

Humans

A microcomputer interface for a digital audio processor-based data recording system.

An inexpensive interface is described that performs direct transfer of digitized data from the digital audio processor and video cassette recorder based data acquisition system designed by Bezanilla (1985, Biophys. J., 47:437-441) to an IBM PC/XT microcomputer. The FORTRAN callable software that drives this interface is capable of controlling the video cassette recorder and starting data collection immediately after recognition of a segment of previously collected data. This permits piecewise analysis of long intervals of data that would otherwise exceed the memory capability of the microcomputer.

Biophysical Phenomena

Microcomputer system for data acquisition and software handling in chromatography.

A complete, powerful yet simple and inexpensive microcomputer system for chromatography is described. It consists of an electronic interface card and an exploiting software, both controlled by an independent microcomputer. The interface includes all necessary circuits for digitizing the chromatographic signal and for controlling the actuators and the sensors connected with the chromatograph. The software, clock-interrupted, allows simultaneous data acquisition, mathematical treatment, connected plotting, and printing, and drives injection valves and gradient elution pumps. This system is both suitable for high-speed capillary gas chromatography and for high-performance liquid chromatography.

Chromatography

A microcomputer application curriculum for emergency medicine residents using computer-assisted instruction.

A microcomputer application curriculum using computer-assisted instruction was developed for emergency medicine residents. Other than introductory comments, the course was composed entirely of disk-based tutorials. No faculty time was necessary. Subjects covered included introduction to microcomputers, the disk operating system; word processing, data bases, and spread sheets. The entire course, including the tutorial floppy disks, was contained in one loose-leaf notebook. Residents who took the course were surveyed. The course took an average of three to six hours to complete. All found the course to be helpful, with word processing being the most useful module. The majority of residents thought that the course was so valuable that it should be given earlier in the residency. Thus, we have moved the course to the first postgraduate year, and the data base and spread-sheet modules have been made optional. The course is easily assembled, requires minimal faculty time, and can be modified to accommodate different hardware and software.

Computer-Assisted Instruction

Diagnosis of complex acid-base disorders: physician performance versus the microcomputer.

Patients with acid-base disturbances that are often complex frequently present to the emergency department. The sometimes hectic nature of the ED can preclude the appropriate quantitative analysis required by these disorders, especially when mixed disturbances are present. A computer program using generally accepted acid-base and electrolyte formulae was developed for use on the Apple II+ or IBM-PC microcomputer. Each of a series of 35 acid-base disturbances incorporating single, double, and triple disorders was correctly identified by the computer in less than 45 seconds. Problem sets based on the same 35 disturbances were presented to 21 physician-subjects at various levels of training from the emergency medicine, internal medicine, pediatrics, surgery, and family practice specialties. Although the physicians were given unlimited time and the necessary formulae to reach a diagnosis, they were requested to perform their analyses in the same fashion used in the ED. Although times varied widely, no physician spent more than five minutes on any problem. The physician correct response rates were 86%, 49%, and 17% for single, double, and triple disorders, respectively. The primary disorder correct response rate was 89% for double disorders and 94% for triple disorders. The primary and secondary disorder correct response rate was 58% for triple disorders. The data suggest that the microcomputer may be beneficial in the rapid assessment of complex disorders.

Acid-Base Imbalance

Resolving multiple overlapping calorimetric transitions by use of a microcomputer: studies on erythrocyte membranes.

Buffer changes and certain drugs cause temperature shifts, amplitude changes, and transition broadening in the differential scanning calorimetric (DSC) analysis of erythrocyte membranes. However, it has been difficult to interpret and quantitate these shifts and changes because the scans are composed of multiple overlapping transitions and because more than one transition may be simultaneously affected. An empirical approach has been developed by using Gaussian modeling to resolve these calorimetric transitions. Data analysis was carried out on a microcomputer using a nonlinear regression program (PCNONLIN) to fit the data scans. These results show that changes in the calorimetric scans of erythrocyte membranes due to alterations in the buffer environment, such as pH and osmolarity, can be resolved by fitting the data scans with the proposed mathematical model and optimizing the resolution parameters with PCNONLIN. In addition, resolution uncovered hidden characteristics that may not have been readily evident. Under certain conditions, for example, apparent transition shifts were shown to actually be amplitude changes and transition broadening. Determination of the limitations and validity of this method was accomplished with simulation studies. This technique offers a simple means for fitting overlapping DSC transitions by use of a commercially available nonlinear regression program that can be run on a microcomputer.

Buffers

A microcomputer-based wearable biofeedback device to improve transfer of treatment in parkinsonian dysarthria.

Achieving transfer of treatment outside the clinic is a problem for almost all individuals with speech disorders but has been particularly difficult in the treatment of patients with Parkinsonism. Given this situation and the frequency of vocal intensity problems in this population, we developed a wearable biofeedback device that could provide a patient with information about speech intensity outside the clinic. Auditory-perceptual and acoustic analyses were performed on audiotaped samples of reading and spontaneous speech recorded in the clinic pre- and posttreatment and at 10- and 20-week follow-ups. Visual feedback of intensity was integrated with auditory cues from a microcomputer that was then worn outside the clinic. The results indicated that the subject did transfer a substantial portion of clinic improvement to the outside environment while wearing the feedback device and suggest the utility of a microcomputer-based wearable device for assessing treatment effects as well as for improving transfer.

Aged

Tabletop versus microcomputer-assisted speech management: stabilization phase.

Few controlled data are available on the efficacy of microcomputers for speech management with children. The focus of this second report in a study series using microcomputers with speech-delayed children (Shriberg, Kwiatkowski, & Snyder, 1986) is on the response stabilization stage of speech management. Two repeated-measures designs were conducted with two samples of preschool children (n = 18) to compare tabletop management with comparable computer-assisted activities. Findings indicate that response stabilization tasks in the two intervention modes were equally effective, efficient, and engaging. Additional analyses suggest that the two modes engage the children in different ways, however, and that children may have individual needs for mode-specific features.

Age Factors