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Microbiology subsystem of a total, dedicated laboratory computer system.

The computer system used by the Microbiology Service of the Clinical Pathology Department, Clinical Center, National Institutes of Health is discussed. This microbiology subsystem is a part of a dedicated on-line laboratory computer system used by the entire department. The laboratory computer is connected on-line to a hospital computer which provides patient admission, transfer, and discharge data. Mark sense worksheets and cathode ray tube terminals are used for result entry and correction. Cumulative patient reports are printed. Results for both active and completed accessions can be easily retrieved on cathode ray terminals in the laboratory. All laboratory data are archived on magnetic tape from which a research data base and microfiched laboratory records are generated. The manner in which the system is integrated in the routine operation of the microbiology laboratory is emphasized. In addition, some of the costs, benefits, liabilities, and pitfalls associated with the introduction of the computer in the laboratory are reviewed. Finally, we have presented our concept of some of the future enhancements to our present system and some of the directions in which any future microbiology system might develop.

Computers↗

New technique for removable implantation of radionuclides in central nervous system neoplasm by ultrasonic guidance.

Introduced here is a new technique for the insertion of removable tubes into a brain tumor guided by a real-time ultrasonic B-mode scanner as a preliminary stage for interstitial brachytherapy of malignant brain tumors. Because tube insertion is conducted while watching in real time the tumor echo displayed on the cathode ray tube, the tube-positioning locations for insertion into the tumor can be freely selected with this technique. Additionally, the length of the tube that remains within the tumor bulk can be easily measured and recorded during the operation. Moreover, in that all these procedures can be carried out in the operating room, the operation will be performed under aseptic conditions and in a shorter time. These are the major advantages of this technique.

Brachytherapy↗

Automated rodent respiratory monitor and histogram computer--a preliminary report.

The system described in this paper was designed to monitor total inhaled volume (V), tidal volume (VT), and respiratory frequency (f) of Fisher rats before, during, and after exposure to cigarette smoke. The systems consists of three major subsystems: plethysmograph, analog signal conditioner, and histogram computer. The volume type whole body plethysmograph incorporates a rubber nose seal. Tidal flow rate (V) from the tube, measured by a pneumotachometer, is integrated by the signal conditioning system to obtain VT and V. Both V and V are displayed on a strip chart recorder. A rat will often exhibit considerable sniffing, especially in the presence of cigarette smoke. Consequently, average tidal volume (VT) and average respiratory frequency (f) are not accurate measurements of typical VT and f. Sensitivity of the system to changes in typical VT and f is important snce the system will be used to evaluate the effects of subtle differences in types of experimental cigarettes. A microprocessor was used in conjunction with a cathode ray tube to compute and display both the VT and respiratory period (T = 1/f) as histograms. From the histograms the most common (typical) VT (mode of the histogram) and the most common T can be easily observed and recorded. The histogram computer also calculates and digitally displays VT and f.

Analog-Digital Conversion↗

High-fidelity electronic display of digital radiographs.

A fully digital radiography system requires high-fidelity electronic display devices that preserve diagnostic quality. Current cathode-ray tube monitors do not meet desired performance criteria for displaying radiographs and have excessive size, weight, and power consumption. Recent developments in flat-panel display technology (in particular active-matrix liquid crystal displays, field-emission displays, and organic light-emitting displays) suggest that high-fidelity, lightweight displays will be available in the near future. Large-size active-matrix liquid crystal display devices have been demonstrated. High brightness can be easily achieved with bright back illumination. Further developments in optical design for monochrome displays should provide high fidelity and improve the angular dependence of the emitted light. Field-emission display devices have attractive emission distribution and potential for low veiling glare. This technology needs to be extended to a large area, and problems with cathode aging and nonuniformity have to be contemplated. Organic light-emitting displays represent a simple and potentially inexpensive display technology with the ability to achieve high image quality. However, extensive research and development is required to achieve large-area manufacturing methods.

Computer Terminals↗

Augmented reality fundus biomicroscopy: a working clinical prototype.

BACKGROUND: To guide treatment for macular diseases and to facilitate real-time image correlation, measurement, and comparison, we developed a method for direct overlay of previously stored photographic and angiographic images onto the real-time slitlamp fundus view. METHODS: Previously acquired fundus photographs and angiography images were digitized. A slitlamp interfaced to a charge-coupled device camera, framegrabber, and computer allowed for real-time acquisition and digitization of slitlamp fundus images that was synchronous with posterior segment examination. Custom-developed video injectors containing a miniature cathode ray tube display allowed for real-time superposition of angiographic images to the fundus view. Registration and tracking algorithms were developed and deployed in C++. The feasibility of this approach was demonstrated in 5 human subjects. RESULTS: The computer-vision algorithms provided robust registration, tracking, and image overlay of previously stored photographic and angiographic images directly onto the real-time fundus view. Accurate tracking was demonstrated with updates at 3 to 5 Hz. Direct overlay of previously stored images confirmed registration accuracy, but examiners preferred a more simple rendering that included only relevant information and eliminated extraneous, potentially confusing image data. CONCLUSIONS: Slitlamp-based video injection of previously stored images allows for accurate, robust, real-time correlation and comparison to the biomicroscopic fundus view in human subjects.

Algorithms↗

Field test results using the BioPEPR cervical smear prescreening system.

BioPEPR is a cathode ray tube scanning device that has been developed for the prescreening of cervical smears. Cervical samples are collected in suspension, syringed, counted and spread across a microscope slide. Feulgen-Thionine with Congo Red is used as the staining procedure. Fields of 6 X 8 mm are scanned at 1 mu resolution, using an intermediate photographic step. Morphologic parameters of the cells are measured, as called for by a hierarchical decision strategy. Analysis speed is currently about 4 min per smear; improvements of at least a factor of four are expected. A field test of BioPEPR is being undertaken in cooperation with a local population screening program. In the study two smears are made from each woman; the first is prepared according to the Papanicolaou technique while the second is prepared and stained according to the BioPEPR methods. In addition to smears from the population screening program a number of possibly abnormal smears are obtained from several gynecological clinics. To date approximately 3500 "second" smears have been analyzed by the BioPEPR system. The results show a missed positive rate on the order of a few percent (no missed positives were more severe than a slight dysplasia), and a false alarm rate of about 24%. A further analysis of the age distribution of the false alarm rate shows that a large proportion came from women above the age of 50; the false alarm rate is about 20% for women under the age of 50.

Adult↗

Risk factors for tumors of the brain and meninges: results from the Adelaide Adult Brain Tumor Study.

A population-based case-control study of incident primary brain tumors in adults was carried out in Adelaide, Australia in the period 1987 through 1990. It included 110 subjects with newly diagnosed primary glioma, 60 subjects with meningioma and 417 controls selected from the Australian Electoral Roll and frequency-matched to cases for age (within 2 years), sex and postal code. Some interesting new associations were found: (1) an increased risk of glioma in women who reported working with cathode-ray tubes (relative risk = 4.1, 95% confidence interval: 1.3-13.2); (2) a decreased risk of glioma in those with a history of allergic diseases (relative risk = 0.5, 95% confidence interval: 0.3-0.9); and (3) an increased risk of meningioma in those exposed to passive smoking from a spouse, especially amongst females (relative risk = 2.7, 95% confidence interval: 1.2-6.1). A pooled analysis of the multi-center group of studies to which the present study belongs should allow more confident claims concerning risk factors for brain tumors.

Adult↗

Real-time color B-scan ultrasonography.

The development and early clinical results of a real-time color B-scan ultrasonoscope are described. This instrument uses color to display detailed echo amplitude information more quantitatively than is possible with gray scale. With real time, dynamic changes are seen during the examination. Conversion of the amplitude information into binary coded decimal code permits separation into ten color steps and also eliminates "blooming" of the cathode ray tube, as seen in black and white. Integrated circuitry is used, providing a portable, relatively inexpensive unit. Early clinical work in ophthalmology is illustrated.

Color↗

INTRAV and ORAL: BASIC interactive computer programs for estimating pharmacokinetic parameters.

Two interactive computer programs, INTRAV and ORAL, were written to permit pharmacokinetic modeling of experimental data and to obtain pertinent values based on derived estimates. Both programs utilize BASIC language and were developed on a microcomputer with graphics capability. Drug concentration in blood, plasma, or serum with time following either nonabsorptive (intravenous) or absorptive (oral or intramuscular) administration is input, and a semilogarithmic display of data appears on a cathode-ray tube (CRT). The user selects limits for various linear segments using a movable cursor. On command, coefficients and exponents for the differential equation which describes those limits is computed and a nonlinear curve is fitted through the data set. Results from statistical tests are available in output formats permitting the user to determine the goodness of the selected limits. Commonly used pharmacokinetic parameters are also computed and appear on the output. Numerous graphic output options are also available to permit comparisons between data sets and/or estimates derived from other computer programs. INTRAV and ORAL were compared with the widely used programs CSTRIP, ESTRIP, and NONLIN. Both INTRAV and ORAL gave estimates which were almost identical with CSTRIP and ESTRIP, whereas those obtained with NONLIN were very similar, although not identical.

Computers↗

Visual evoked cortical potentials from transient dark and bright stimuli. Selective 'on' and 'off-pathway' testing?

The superior hemifields of five normal left eyes were stimulated by novel equal and opposite contrast pattern onset stimuli which were generated on a cathode ray tube. Patterns consisted of 144 discs, each subtending 60 min arc at the viewing distance of 40 cm and were separated by a distance equal to their diameter. Equal and opposite light changes were created by presenting the disc patterns with different luminance values on a uniform constant background (20 cd/m2). Transient visual evoked cortical potentials to the appearance and disappearance of the patterns were recorded separately and analysed. Significant amplitude differences between the responses to bright and dark stimuli were observed with light increment responses being 36-53% larger than the light decrement responses for pattern on-set and 54-80% larger for pattern off-set respectively. This finding is attributed to the difference in the input to the ON and OFF Parallel Pathways which are known to carry light increment and decrement information respectively, as well as differences in the metabolic and discharge rates of these pathways.

Adult↗

Cell proliferation in the embryonic quail uropygial gland during placode stage to lumen formation.

The uropygial gland is one of the epidermal derivatives in birds. In the beginning of the morphogenesis of the uropygial gland of the quail embryo, placode formation occurs: Epidermal basal cells remain cuboidal until day 7 of incubation. At day 8 they begin to elongate, become columnar, and develop placode-like structure at day 9. To examine the proliferative activity of the epidermal basal cells, we recorded positions of [3H]-thymidine-labelled nuclei in serial sections by autoradiography (ARG) using a digitizer and a microcomputer. The distribution pattern of labelled nuclei was reconstituted and redisplayed on the cathode ray tube (CRT) as two-dimensional computer graphics. Three-dimensional reconstitution of the same serial sections revealed that cuboidal basal cells in the presumptive uropygial placode became columnar. Unlike the feather and scale placodes, the uropygial placode possessed no resting period of DNA synthesis. The labelling index of the uropygial placode increased considerably compared with that of nonplacode epidermis. No dermal condensation was observed beneath the uropygial placode.

Animals↗

Multiplication noise in the human visual system at threshold. 3. The role of non-Poisson quantum fluctuations.

Several kinds of light used in vision experiments produce photon statistics that are distinctly non-Poisson. Representative examples are light from a cathode-ray tube and an image-intensifier device. For the class of vision experiments in which the photon statistics play an important role, excess fluctuations produced by such light sources can alter the observed results and obscure the visual mechanisms being studied. They must therefore be accounted for in a proper way. We use the results of a Hecht-Shlaer-Pirenne type experiment, carried out with modulated Poisson light, to illustrate the point. Sensitivity and modulation depth, as well as sensitivity and reliability, are shown to be traded against each other. Finally, we demonstrate that number-state light, which is comprised of photons of an ideal kind, provides the ultimate tool for extracting information about the intrinsic noise distribution in the visual system at threshold. The state of the art in producing such light is discussed.

Humans↗

A fluorescence cytophotometer operated under computer control for multi-parameter cell analysis.

A new type of fluorescence cytophotometer has been developed for multi-parameter cell analysis (Olympus BH2-QRFL). For multi-color fluorescence cytophotometry, this instrument is equipped with four sets of interchangeable filters, each consisting of an excitation filter, a dichroic mirror with a barrier filter, and a measuring filter. For permitting automatic operation of the filter sets, the cytophotometer is connected on line with a personal computer (HP 85F). A desired sequence of filter sets can be memorized in the software and multiple cellular constituents can be rapidly and consecutively determined on a single cell basis. All data are stored in the same computer and can be retrieved for further statistical analysis and display either in tabular form, or as histogram, correlation histograms, two-dimensional scatter plot, or two-dimensional frequency distribution histogram, on the CRT (cathode ray tube) with simultaneous hard copy. As an example of multiparameter cell analysis, combined protein and DNA measurements were performed on normal, border-line, and cancerous gynecological cytology specimens by using the ninhydrin-Schiff and Feulgen techniques.

Cell Separation↗

Limits on literal processing during idiom interpretation.

Two experiments investigated the extent to which literal processing occurs in comprehending figurative idiomatic expressions. Subjects read stories on a cathode-ray tube (CRT). Target phrases, some of which were idioms, contained nouns which were potential anaphors of previously mentioned referents. A method developed by Dell, McKoon and Ratcliff (1983) was used to determine whether subjects carried out semantic processing resulting in activation of the referents of those anaphors. In Experiment 1the targets consisted of either an idiom or a literal phrase, each including the same potential anaphor, or a control phrase. Results suggest that the preceding referent was activated by the anaphor in the literal phrase, but not by the potential anaphor in the idiomatic phrase. Experiment 2 showed that these results were not due to differences in the materials used. These results are interpreted as supporting the hypothesis that when an idiomatic phrase is interpreted figuratively full literal semantic processing of that phrase is not necessarily carried out.

Adult↗

Detection sensitivity to light offsets is abnormal in glaucomatous visual field.

The detection thresholds in the central visual fields of glaucomatous (n = 21), ocular hypertensive (n = 21) and normal (n = 13) individuals were tested with both light decrements (offsets = dark spots) on a cathode ray tube (CRT) and light increments (onsets = bright spots) on a bowl projection perimeter. Both types of stimuli were of equal surface area (Goldmann size IV = 16 mm2) and duration (200 milliseconds) on a 10 cd/m2 background intensity. Computerized threshold testing with light offsets on CRT could document the glaucomatous visual field loss with high accuracy and might indicate early glaucomatous visual field loss missed by the conventional light onset stimuli.

Adult↗

Topographical reproducibility of small scotoma using computerised dynamic fixation target.

The computer assisted dynamic fixation technique uses the patient's eye movements to locate the test stimulus in the central visual field in relation to a randomly meandering fixation target. The patient looks at the moving fixation target on a high resolution monitor and tries to keep it inside a circle using a joystick. The stimuli are presented at predetermined locations in a seemingly random manner and the awareness of the stimuli is registered by the patient pressing the joystick button. That novel fixation maintenance technique has been combined with suprathreshold static light offset (dark-on-bright-light decrement) stimuli created on a cathode ray tube and used in mapping of the physiological blind spot in 10 healthy eyes. Each eye was examined twice with the same test program in order to document the repeatability of the results. On two consective tests, the physiological blind spot measured an average of 5.7 degrees horizontally and 6.4 degrees vertically, using 15% (17 dB) contrast, 16 mm2, single intensity offset stimuli. The moving eye method and the light offset stimuli, on repeated testing, yielded an average topographical reproducibility rate of 73% in mapping of the scotomas, with an average of 1.4 degrees and 0.6 degree variability in the vertical and horizontal dimensions of the blind spot respectively.

Adult↗

A real-time library of medicine for practicing physicians.

An on-line, practice-oriented library system now exists in prototype form which can act as a central repository of medical information. The source data are gathered by the residents at Shands Teaching Hospital and Clinics at the University of Florida as part of their rotation through clinical pathology. The information is continually updated and reviewed every 3 months by new residents and area specialists. Plans are under way to make this pool of information accessible to all levels of the health care team in an instantaneously addressable fashion via CRT (cathode ray tube). After many months of resource development, we have major sections of an on-line dictionary of clinical and surgical pathology and expect to expand this in the future to include a medical problem-oriented indexing system, a disease-oriented library, and a page-associated file of reference.

Computers↗

OKAS-3D: optoelectronic jaw movement recording system with six degrees of freedom.

OKAS-3D is a further development of the single floating circle target tracker. This tracker consists of a cathode ray tube display, a lens in front of the display and a circular light-sensitive photocell placed in the image field of the lens. A small circular trace generated on the screen is focused around the photocell. The sinusoidal electrical output of the photocell contains all the relevant information regarding the position of the photocell relative to the image of the circular light trace. This gives the tracker the properties of a servo-controller with position feedback. In OKAS-3D three pairs of photocells are located on two lightweight frames attached to the upper and lower frontal teeth by individually adapted clutches. By using the formulas of rigid body mathematics, the motion of any point of the mandible can be reconstructed. The system permits a high sampling frequency of at least 300 Hz per photocell co-ordinate. The noise, linearity and accuracy are better than 0.08 mm, 0.07 mm and 0.13 mm for points in the lower incisal region, and better than 0.25 mm, 0.17 mm and 0.27 mm for points in the condylar region. Thus jaw movements can be recorded with a high spatial and temporal resolution.

Biomedical Engineering↗