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PubMed1998

The advantages of digital over analog recording techniques.

In the past few years digital technology has brought EEG and evoked potentials into emergency rooms, intensive care units and operating rooms with a variety of automatic data trending. Networking of these systems makes access to clinical neurophysiologists nearly immediate. Digital EEG has made montage reformatting and quantitation of parameters readily available. Increased spatial and temporal resolution is available with routine EEG, and combined topographic and frequency mapping of a given potential, spike or seizure focus is possible. In the future, these and other features such as dipole mapping and cognitive EP analysis will be available on a routine basis.

Animals↗
PubMed1992

Artificial intelligence in automated classification of rat vaginal smear cells.

Microscopic examination of vaginal smears has been used routinely to determine the stage of the estrous cycle of female rats in reproductive research. The stage of the estrous cycle is based on relative counts of nucleated epithelial cells, cornified epithelial cells and leukocytes. The purpose of this project was to explore automation of vaginal smear analysis using image processing and artificial intelligence techniques. A fully connected back-propagation neural network was used to locate all potential objects in a digitized scene. A unique algorithm was then employed to center a subsequent sampling box to collect pixel intensity values from the red and green components of each image. A final neural network was used in the classification of cell type. Neural networks were used because of their ability to generalize among input patterns and to tolerate extraneous noise due to variations in staining artifacts and aberrant illumination of the microscope field. This preliminary cell diagnosing system not only provides the basis for the fully automated system but also provides a method by which many other cytologic image processing problems can be automated.

Animals↗
PubMed1998

Joslin Vision Network Validation Study: pilot image stabilization phase.

PURPOSE: This preliminary study is designed to evaluate the quality of initial images obtained using the Joslin Vision Network (JVN) image capture and retrieval system. METHODS: Digitized images of 18 patients (36 eyes) were obtained using Topcon Non-mydriatic Fundus Camera and various imaging protocols as described for each series of images. Level of retinopathy ranged from no diabetic retinopathy to proliferative diabetic retinopathy. Images were reviewed and evaluated in comparison to medical record notes and Early Treatment Diabetic Retinopathy Study (ETDRS) seven-standard field stereoscopic 35-mm retinal fundus photographs--when available--to determine the ability of JVN digitized images to allow appropriate diagnosis and clinical management. JVN images were also evaluated for presence of photographic artifacts and stereoscopic presentation. The various displays and relative value of each JVN display were also evaluated. RESULTS: Using combinations of JVN image displays, JVN images were shown to match diagnosed level of diabetic retinopathy as determined from record notes and/or ETDRS seven-standard field stereoscopic 35-mm retinal fundus photography. Viewing images with various combinations of JVN image displays delineates possible sources of artifacts in JVN images. Areas to guide future image capture and image reading are identified. CONCLUSIONS: The JVN image capture system and reading of images by certified readers should allow appropriate photodiagnostic information to support the JVN, the diabetes mellitus disease management telemedicine initiative of the Joslin Diabetes Center. A rigid, full-scale, masked study to compare the Joslin Vision Network to seven-standard field stereoscopic 35-mm retinal fundus photography should be pursued to validate the image-gathering and image-reading strategy to support the Joslin Vision Network.

Adult↗
PubMed2000

Transmission failure rate for computed tomography examinations in a filmless imaging department.

The purpose of the study was to determine the frequency and causes of unsuccessful computed tomography (CT) transmissions in a filmless imaging department and to determine the added efficiency gains provided by the sequential addition of modality worklist software and a major network upgrade. Prospective data on CT transmission error rates were recorded over an 18-month period. During the study interval, modality worklist functionality was added, followed by a network upgrade. Failed transmissions were categorized as to the source of the error (human v technical), and the specific problem encountered. Prior to the introduction of modality worklist software, the initial CT transmission failure rate was 7.6%, which was primarily the result of human error (69%), in the form of data entry error. Upon the introduction of modality worklist software, the transmission failure rate decreased to 3.5%, with human error accounting for only 16% of all failed transmissions. The subsequent addition of a network upgrade from shared Ethernet to switched Ethernet further reduced the transmission failure rate to 2.0%, which was believed to be the result of a reduction in the number of network collisions. Other sources of failed transmission occur at the levels of the CT scanner (network interface card), picture archiving and communication system (PACS)/hospital information system (HIS) interface, and modality gateway. When planning the transmission from film-based to filmless operation, one should consider various hardware, software, and infrastructural requirements to ensure successful PACS implementation. Software upgrades, in the form of modality worklist software, serve to improve technologist productivity by minimizing data entry error. Infrastructural changes, in the form of network upgrading, ensure proper dissemination of electronic data with decreased frequency of network collisions. Collectively, these improvements lead to enhanced transmission of digital images, resulting in productivity gains within the filmless CT department.

Computer Communication Networks↗
PubMed1995

Pediatric skeletal age: determination with neural networks.

PURPOSE: To develop a neural network to calculate skeletal age based on measurements taken from digitized hand radiographs. MATERIALS AND METHODS: From a database of 521 hand radiographs obtained in healthy patients, four parameters were calculated from seven linear measurements and were used to train a neural network, with use of the jackknife method, to calculate skeletal age. The results were compared with those of an experienced pediatric radiologist using a standard pediatric skeletal atlas. RESULTS: The mean difference from biologic age for the neural network was -0.261 years +/- 1.82 (standard deviation) and for the radiologist, -0.232 years +/- 1.54; this difference was not significantly different (P = .67, Wilcoxon signed rank test). Skeletal age determined by the neural network was closer to the biologic age than that assigned by the radiologist in 243 of 521 cases (47%). CONCLUSION: A simple neural network may assist radiologists in the assessment of skeletal age.

Adolescent↗
PubMed1997

Image bank, diagnostic codification and telediagnosis in hematology.

Recent technological improvements which permit transmission and discussion of color images with good resolution and in real time may become very useful for hematological and histopathological applications. The workstations used a PC Pentium, 16 Mo RAM 1,6 Go of hard disk, including a laser-reader for CD-ROM and network cards. Applications are developed under Windows 95. The system allows to digitalize, compress and decompress any kind of colored or black and white images according to the International Norms, JPEG. The storage is managed by a specific software according to specific classification for diagnostic nomenclature. It can store typical, less typical and atypical images of examples of pathology which can contribute to the constitution of a digitized bank of images and CD-ROM. The system used have been launched to allow pathology image transmission on ISDN networks for diagnosis assessment. Standardization of nomenclature which has been achieved both for immunophenotyping and cytogenetics is necessary for the cyto-anatomical lesions in the specialized field of hematology. In using the major published recommendations (FAB, EGIL, REAL etc.), a comprehensive approach of nomenclature for our image data base is proposed through a 500 item Thesaurus, which have been written simultaneously as a multilangage version.

CD-ROM↗
PubMed2005

[Computerization and the importance of information in health system, as in health care resources registry].

The possibilities of creating a health care resources registry and its operating in Croatia as well as the importance of information in health system are described. At the Croatian Institute of Public Health, monitoring of human resources is performed through the national Health Workers Registry. It also covers basic data on all health units, bed capacities of health facilities included. The initiated health care computerization has urged the idea of forming one more database on physical resources, i.e. on registered medical devices and equipment, more complete. Linking these databases on health resources would produce a single Health Care Resources Registry. The concept views Health Care Resources Registry as part of the overall health information system with centralized information on the health system. The planned development of segments of a single health information system is based on the implementation of the accepted international standards and common network services. Network services that are based on verified Internet technologies are used within a safe, reliable and closed health computer network, which makes up the health intranet (WAN--Wide Area Network). The resource registry is a software solution based on the relational database that monitors history, thus permitting the data collected over a longer period to be analyzed. Such a solution assumes the existence of a directory service, which would replace the current independent software for the Health Workers Registry. In the Health Care Resources Registry, the basic data set encompasses data objects and attributes from the directory service. The directory service is compatible with the LDAP protocol (Lightweight Directory Access Protocol), providing services uniformly to the current records on human and physical resources. Through the storage of attributes defined according to the HL7 (Health Level Seven) standard, directory service is accessible to all applications of the health information system. Directory service does not follow the history of attribute changes, and is optimized for a large number of authorizing inquiries. With it, one follows the following objects and attributes: persons, groups of people (patients, physicians, other personnel), roles (right of access and administrator permissions), organizational units, unit locations, devices and services (according to the list of services and procedures). One can add to the Health Care Resource Registry such attributes as are nonessential for inclusion in the directory service, but are of public health value. Authentication, authorization and digital signature are done by means of Smart Cards, which are used as protective elements against access to system functions, and simultaneously as a physical medium for the storage of the official certificate with which documents are signed digitally. As FINA (state financial control agency) has completed a system for certificate issuance and verification, the option of official digital signature is also available as a computer network service. Any changes taking place in the directory service are transferred by XML messages to a separate part of the Registry that reads them and automatically modifies records in the relational database. Because data input and data changes are made in health units, this makes the data updated and directly connected with health working operations. This avoids all one-time data collection campaigns using form filling about the devices and equipment in the future. As it is very difficult to monitor from a central standpoint how accurate and update the information is, it is necessary to delegate the permissions and duties associated with making changes to the directory service. By this organizational setup, the time needed to ensure data quality control is reduced. In the case described, the Health Care Resource Registry becomes an indicator of change, acquiring certain characteristics of an analytical system. An analysis of topical data renders possible proactive action and makes more effective the planning and utilization of available resources. Providing answers on the current data quickly could also be important to solution-seeking in emergencies. The present proposal to establish the Registry is intended to facilitate the future process of planning and striking a balance between investments in human and physical resources. For health expenditure control, having reliable information related to the use and purchase of new medical technology is particularly important. World Health Organization and European Union have also emphasized the need to develop new indicators in this area.

Croatia↗
PubMed2002

Optimal neural network architecture selection: improvement in computerized detection of microcalcifications.

RATIONALE AND OBJECTIVES: The authors evaluated the effect of optimal neural network architecture selection on the performance of a computer-aided diagnostic system designed to detect microcalcification clusters on digitized mammograms. MATERIALS AND METHODS: The authors developed a computer program to detect microcalcification clusters automatically on digitized mammograms. Previously, they found that a properly selected and trained convolution neural network (CNN) could reduce false-positive (FP) findings and therefore improve the accuracy of microcalcification detection. In the current study, they evaluated the effectiveness of the CNN optimized with an automated optimization technique in improving the accuracy of the microcalcification detection program, comparing it with the manually selected CNN. An independent test data set was used, which included 472 mammograms selected from the University of South Florida public database and contained 253 biopsy-proved malignant clusters. RESULTS: At an FP rate of 0.7 cluster per image, the film-based sensitivity was 84.6% for the optimized CNN, compared with 77.2% for the manually selected CNN. For clusters imaged on both craniocaudal and mediolateral oblique views, a cluster could be considered detected when it was detected on one or both views. For this case-based approach, at an FP rate of 0.7 per image, the sensitivity was 93.3% for the optimized and 87.0% for the manually selected CNN. CONCLUSION: The classification of true and false signals is an important step in the microcalcification detection program. An optimized CNN can effectively reduce FP findings and improve the accuracy of the computer-aided detection system.

Breast Neoplasms↗
PubMed1992

Steady state dynamics of intermediate filament networks.

We have conducted experiments to examine the dynamic exchange between subunit and polymer of vimentin intermediate filaments (IF) at steady state through the use of xrhodamine-labeled vimentin in fluorescence recovery after photobleaching (FRAP) analysis. The xrhodamine-vimentin incorporated into the endogenous vimentin IF network after microinjection into fibroblasts and could be visualized with a cooled charge-coupled device (CCD) camera and digital imaging fluorescence microscopy. Bar shaped regions were bleached in the fluorescent IF network using a beam from an argon ion laser and the cells were monitored at various times after bleaching to assess recovery of fluorescence in the bleached zones. We determined that bleached vimentin fibers can recover their fluorescence over relatively short time periods. Vimentin fibers in living cells also can exhibit significant movements, but the recovery of fluorescence was not dependent upon movement of fibers. Fluorescence recovery within individual fibers did not exhibit any marked polarity and was most consistent with a steady state exchange of vimentin subunits along the lengths of IF.

3T3 Cells↗
PubMed1998

A software sensor using neural networks for detection of patient workload.

The morphology of intracardiac electrograms (IEGMs) was used for pacemaker patient workload estimation. The body posture also was studied as another characteristic. The IEGMs were obtained and recorded via temporary transcutaneous leads connected to the implanted pacemaker. IEGMs were recorded during exercise and at rest. Recordings at rest were performed in different body positions. The morphology was analyzed visually in order to observe changes due to workload and posture. The recordings were digitized and processed by a computer-simulated neural network. The network was used as an automatic IEGM classifier based on the morphology. Our results show that the morphology of the IEGM may be used as an indicator of patient workload and body posture. The necessary information is found mainly in the ST segment. We conclude that neural networks seem to be useful in an active cardiac device.

Aged↗
PubMed1992

Communication in digital radiology.

The long-distance transfer of dental radiographs was explored as early as the 1920s. The practicality of such image transfer has improved through advances in telecommunications and computer networks (both hardware and software) and the emerging trends towards direct and indirect digital imaging techniques for recording oral and maxillofacial radiographs. This paper reviews the current status of communication in digital dental radiology. It is illustrated by personal observations from a variety of demonstration projects.

Computer Communication Networks↗
PubMed2000

The morphometric analysis and recognition an amyloid plaque in microscope images by computer image processing.

This paper presents an approach of the two-dimensional image processing application in recognition of amyloid plaque in microscope images of the brain tissues. The authors propose to create universal amyloid plaque computer pattern and special multivariate image segmentation techniques based on collected images and statistical information. This recognition image procedure is divided into 3-dimensional statistical colour and morphological shape identifications. The developed computer system will collect and store image data and exchange them by network with other collaborated systems.

Alzheimer Disease↗
PubMed1985

"Neural" computation of decisions in optimization problems.

Highly-interconnected networks of nonlinear analog neurons are shown to be extremely effective in computing. The networks can rapidly provide a collectively-computed solution (a digital output) to a problem on the basis of analog input information. The problems to be solved must be formulated in terms of desired optima, often subject to constraints. The general principles involved in constructing networks to solve specific problems are discussed. Results of computer simulations of a network designed to solve a difficult but well-defined optimization problem--the Traveling-Salesman Problem--are presented and used to illustrate the computational power of the networks. Good solutions to this problem are collectively computed within an elapsed time of only a few neural time constants. The effectiveness of the computation involves both the nonlinear analog response of the neurons and the large connectivity among them. Dedicated networks of biological or microelectronic neurons could provide the computational capabilities described for a wide class of problems having combinatorial complexity. The power and speed naturally displayed by such collective networks may contribute to the effectiveness of biological information processing.

Animals↗
PubMedDate not supplied

Preparing a business justification for going electronic.

Exponential advances in the technology sector and computer industry have benefited the science and practice of radiology. Modalities such as digital radiography, computed radiography, computed tomography, magnetic resonance imaging, ultrasound, digital angiography, and gamma cameras are all capable of producing DICOM compliant images. Text can likewise be acquired using voice recognition technology (VRT) and efficiently rendered into a digital format. All of these digital data sets can subsequently be transferred over a network between machines for display and further manipulation on workstations. Large capacity archiving units are required to store these voluminous data sets. The enterprise components of radiology departments and imaging centers--radiology information systems (RIS) and picture archiving and communications systems (PACS)--have thus undergone a transition from hardcopy to softcopy. When preparing to make transition to a digital environment, the first step is introspective. A detailed SWOT (strengths, weaknesses, opportunities and threats) analysis, with a focus on the status of "electronic preparedness," ensues. The next step in the strategic planning process is to formulate responses to the following questions: Will this technology acquisition provide sufficient value to my organization to justify the expense? Is there a true need for the new technology? What issues or problems does this technology address? What customer needs will this technology satisfy today and tomorrow? How will the organization's shareholders benefit from this technology? The answers to these questions and the questions that they in turn generate will stimulate the strategic planning process to define demands, investigate technology and investment options, identify resources and set goals. The mission of your radiology center will determine what you will demand from the electronic environment. All radiology practices must address the demand of clinical service. Additional demands based on your mission may include education and research. The investigation of options is probably the most time consuming portion of the analysis. It is in this stage where the system architecture is drafted. Important contributions must be solicited from your information technology division, radiologists and other physicians, hospital administration and any other service where the use of imaging technology information is required and beneficial. Vendors and consultants can be extremely valuable in generating workflow diagrams, which include imaging acquisition components and imaging display components. A request for proposal (RFP) may facilitate this step. A detailed inventory of imaging equipment, imaging equipment locations and use, imaging equipment DICOM compatibility, imaging equipment upgrade requirements, reading locations and user locations must be obtained and confirmed. It is a good idea to take a careful inventory of your resources during the process of investigating system architecture and financial options. An often-ignored issue is the human resource allocation that is required to implement, maintain and upgrade the system. These costs must be estimated and included in the financial analysis. Further, to predict the finances of your operation in the future, a solid understanding of your center's historical financial data is required. This will enable you to make legitimate and reasonable financial calculations using incremental volumes. The radiology center must formulate and articulate discrete clinical and business goals for the transition to a digital environment that are consistent with the institutional or enterprise mission. Once goals are set, it is possible to generate a strategic plan. It is necessary to establish individual accountability for all aspects of the planning and implementation process. A realistic timetable should be implemented. Keep in mind that this is a dynamic process; technology is rapidly changing, as are clinical service demands and regulatory initiatives. It is therefore prudent to monitor the process, make appropriate revisions when necessary and address contingencies as they arise.

Capital Expenditures↗
PubMed1996

Automated particle classification based on digital acquisition and analysis of flow cytometric pulse waveforms.

In flow cytometry, the typical use of front-end analog processing limits the pulse waveform features that can be measured to pulse integral, height, and width. Direct digitizing of the waveforms provides a means for the extraction of additional features, for example, pulse skewness and kurtosis, and Fourier properties. In this work, we have first demonstrated that the Fourier properties of the pulse can be employed usefully for discrimination between different types of cells that otherwise cannot be classified by using only time-domain features of the pulse. We then implemented and evaluated automatic procedures for cell classification based on neural networks. We established that neural networks could provide an efficient means of classification of cell types without the need for user interaction. The neural networks were also employed in an innovative manner for analysis of the digital flow cytometric data without feature extraction. The performance of the neural networks was compared with that of a more conventional means of classification, the K-means clustering algorithm. Neural networks can be realized in hardware, and this, in addition to their highly parallel architecture, makes them an important potential part of real-time analysis systems. These results are discussed in terms of the design of a real-time digital data acquisition system for flow cytometry.

Animals↗
PubMed1989

Distribution and spatial geometry of dopamine interplexiform cells in the rat retina: I. Developing retina.

The morphology and distribution of dopaminergic interplexiform cells were analyzed in 9-day-old rat retinas processed as wholemounts for tyrosine hydroxylase immunohistochemistry. The mean number of dopaminergic interplexiform cells was estimated as about half of the total number of dopaminergic neurons in the immature retina, with a higher density in the temporal retina. Four interplexiform cells were individually analyzed and reconstructed with a computer system. Their arborizations could be divided into three different regions based on both their morphological features and their position within the retinal layers: (1) an internal arborization, spreading at the margin between the inner nuclear layer and the inner plexiform layer, composed of long, thick, somatofugal dendrites branching at acute angles, (2) an external arborization in the middle of the inner nuclear layer, formed by short, thin, varicose, recurved, axon-like processes branching at right angles, (3) and one or more scleral process(es), originating either from the cell body or from the internal arborization, running toward the outermost cell row of the INL, some of which reached the outer plexiform layer. Finally, analysis of the arborization network by computer simulations based on the 4 digitalized cells was compared with a nearest-neighbour analysis of cell body distribution. It showed that cell bodies are almost randomly distributed--at least in the inferior retina--but that an adjustment of dendritic growth and orientation probably occurs to ensure a homogeneous coverage of the retina with a constant degree of overlap in the adult. This report represents the first three-dimensional computer reconstruction of chemically identified neurons in the retina.

Animals↗
PubMed1995

Information management in the cardiology department. An analysis of current options for replacing cinefilm.

A major cost component in cardiac angiography is the use of cinefilm for archiving. In addition, cinefilm is difficult to reproduce. There is only one unique archival copy, and if it becomes torn, or lost, it cannot be replaced. Consequently, physicians and administrators looking to save time, increase efficiency and cut costs are also looking for ways to eliminate cinefilm use. Major driving forces that must lead to a replacement of cinefilm are: Cost reduction and Efficiency improvement. The challenge in cardiology is to find a digital cardiac archiving solution that meets the three basic requirements: 1. Cost effectiveness, 2. Ability to perform the basic clinical functions: Review, Exchange and Archive, and 3. Standard format for exchange. A single medium solution, based on CD technology, can fulfill all requirements for review, exchange and archiving. This CD solution, based on CD-Recordable must conform to the DICOM standard for exchange as defined by the ACC/NEMA committee. As advanced technology becomes available, further efficiency improvement can be achieved as extensions to the digital cine replacement based on CD technology. Such networked, multi media solutions are based on a hierarchical storage management concept, incorporate short term archives for on-line availability, and long term archives based on CD for immediate retrieval and exchange.

Cardiac Catheterization↗