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PubMed1989

[Professional organ procurement as a prerequisite for attaining the necessary transplantation frequency: experiences with organ distribution at the transplantation center in Vienna].

In the years 1965 to 1988 one or more organs were harvested for the purpose of transplantation from 649 brain dead organ donors reported to the Vienna transplantation centre. Based on a 1982 law regulating organ donation a large number of initiatives aiming at the improvement of the organ procurement system have taken place. In particular, the introduction of a decentralized donor guidance and organ retrieval system, a few information campaigns, as well as the introduction of full-time transplantation coordinators have significantly increased the number of organ donors. This development has made the Vienna transplantation centre one of the largest centres in Europe and has recently resulted in the achievement of a virtual balance between the increase of patients on the waiting list and the growth of the rate of transplantations performed. If this organ procurement policy is consistently continued in the years to come, there is a good chance of ensuring sufficient supply of organs for all patients on waiting lists, at least within the Viennese area.

Austria↗
PubMed1998

Towards knowledge-based retrieval of medical images. The role of semantic indexing, image content representation and knowledge-based retrieval.

Medicine is increasingly image-intensive. The central importance of imaging technologies such as computerized tomography and magnetic resonance imaging in clinical decision making, combined with the trend to store many "traditional" clinical images such as conventional radiographs, microscopic pathology and dermatology images in digital format present both challenges and an opportunities for the designers of clinical information systems. The emergence of Multimedia Electronic Medical Record Systems (MEMRS), architectures that integrate medical images with text-based clinical data, will further hasten this trend. The development of these systems, storing a large and diverse set of medical images, suggests that in the future MEMRS will become important digital libraries supporting patient care, research and education. The representation and retrieval of clinical images within these systems is problematic as conventional database architectures and information retrieval models have, until recently, focused largely on text-based data. Medical imaging data differs in many ways from text-based medical data but perhaps the most important difference is that the information contained within imaging data is fundamentally knowledge-based. New representational and retrieval models for clinical images will be required to address this issue. Within the Image Engine multimedia medical record system project at the University of Pittsburgh we are evolving an approach to representation and retrieval of medical images which combines semantic indexing using the UMLS Metathesuarus, image content-based representation and knowledge-based image analysis.

Abstracting and Indexing↗
PubMed2000

Biobibliometrics: information retrieval and visualization from co-occurrences of gene names in Medline abstracts.

Successful information retrieval from biomedical literature databases is becoming increasingly difficult. We have developed a prototype system for retrieving and visualizing information from literature and genomic databases using gene names. The premise of our work is that, if two genes have a related biological function, the co-occurrence of two gene names (or aliases of those genes) within the biomedical literature is more likely. From a collection of Medline documents, we have extracted the number of co-occurrences of every pair of Saccharomyces cerevisiae genes. The query is automatically conflated to include gene aliases as well. In addition, the retrieved document set can be filtered by the user with a MeSH term. From this co-occurrence data we construct a matrix that contains dissimilarity measurements of every pair of genes, based on their joint and individual occurrence statistics. A graph is generated from this matrix, with node and edge inclusion being determined by a user-defined threshold. Nodes of the graph represent genes, while edge lengths are a function of the occurrence of the two genes within the literature. Nodes can be hypertext-linked to sequence databases, while edges are linked to those Medline documents that generated them. The system is a tool for efficiently exploring the biomedical information landscape and may act as a inference network.

Databases, Factual↗
PubMed2001

Virtual reality based surgical assistance and training system for long duration space missions.

Access to medical care during long duration space missions is extremely important. Numerous unanticipated medical problems will need to be addressed promptly and efficiently. Although telemedicine provides a convenient tool for remote diagnosis and treatment, it is impractical due to the long delay between data transmission and reception to Earth. While a well-trained surgeon-internist-astronaut would be an essential addition to the crew, the vast number of potential medical problems necessitate instant access to computerized, skill-enhancing and diagnostic tools. A functional prototype of a virtual reality based surgical training and assistance tool was created at our center, using low-power, small, lightweight components that would be easy to transport on a space mission. The system consists of a tracked, head-mounted display, a computer system, and a number of tracked surgical instruments. The software provides a real-time surgical simulation system with integrated monitoring and information retrieval and a voice input/output subsystem. Initial medical content for the system has been created, comprising craniofacial, hand, inner ear, and general anatomy, as well as information on a number of surgical procedures and techniques. One surgical specialty in particular, microsurgery, was provided as a full simulation due to its long training requirements, significant impact on result due to experience, and likelihood for need. However, the system is easily adapted to realistically simulate a large number of other surgical procedures. By providing a general system for surgical simulation and assistance, the astronaut-surgeon can maintain their skills, acquire new specialty skills, and use tools for computer-based surgical planning and assistance to minimize overall crew and mission risk.

Aerospace Medicine↗
PubMed2006

Enhancing access to the Bibliome: the TREC 2004 Genomics Track.

BACKGROUND: The goal of the TREC Genomics Track is to improve information retrieval in the area of genomics by creating test collections that will allow researchers to improve and better understand failures of their systems. The 2004 track included an ad hoc retrieval task, simulating use of a search engine to obtain documents about biomedical topics. This paper describes the Genomics Track of the Text Retrieval Conference (TREC) 2004, a forum for evaluation of IR research systems, where retrieval in the genomics domain has recently begun to be assessed. RESULTS: A total of 27 research groups submitted 47 different runs. The most effective runs, as measured by the primary evaluation measure of mean average precision (MAP), used a combination of domain-specific and general techniques. The best MAP obtained by any run was 0.4075. Techniques that expanded queries with gene name lists as well as words from related articles had the best efficacy. However, many runs performed more poorly than a simple baseline run, indicating that careful selection of system features is essential. CONCLUSION: Various approaches to ad hoc retrieval provide a diversity of efficacy. The TREC Genomics Track and its test collection resources provide tools that allow improvement in information retrieval systems.

Journal Article↗
PubMedDate not supplied

Problem-oriented prefetching for an integrated clinical imaging workstation.

Prefetching methods have traditionally been used to restore archived images from picture archiving and communication systems to diagnostic imaging workstations prior to anticipated need, facilitating timely comparison of historical studies and patient management. The authors describe a problem-oriented prefetching scheme, detailing 1) a mechanism supporting selection of patients for prefetching via characterizations of clinical problems, using multiple data sources (picture archiving and communication systems, hospital information systems, and radiology information systems), classifying patients into cohorts on the basis of their medical conditions (e.g., lung cancer); and 2) prefetching of multimedia data (imaging, laboratory, and medical reports) from clinical databases to enable the viewing of an integrated patient record. Preliminary evaluation of the prefetching algorithm using classic information retrieval measures showed that the system had high recall (100 percent), correctly identifying and retrieving data for all patients belonging to a target cohort, but low precision (50 percent). A key finding during testing was that the recall of the system was increased through the use of multiple data sources (compared with one data source), because of better patient descriptors. Medical problems and patient cohorts were more specifically defined by combining information from heterogeneous databases.

Algorithms↗
PubMed1999

Implementation and evaluation of workflow based on hospital information system/radiology information system/picture archiving and communications system.

The purpose of this presentation is to review and evaluate computerized workflow of selected sites that have integrated systems of the hospital information system (HIS), radiology information system (RIS), and picture archiving and communications system (PACS). We then focus on some essential points of integration of those systems, such as avoiding multiple entries of patients demographic data, prefetching current and previous images to the correspondent workstations, and workflow management. To realize them by integrating multiple subsystems such as HIS/RIS/PACS integration, there must be exchange of the workflow control information, and consistency of the information between subsystems.

Computer Systems↗
PubMed2003

Effects of visual deprivation on the organization of the semantic system.

Early onset blindness provides a lesion model to investigate whether experience-dependent mechanisms subtend the functional anatomy of semantic retrieval. In particular, visual deprivation might alter the neural systems underlying retrieval of semantic information that is acquired via visual experience. Using functional MRI, we demonstrate that both early blind and sighted subjects activate a left-lateralized fronto-temporal 'core' semantic retrieval system and show common effects for retrieval of visually experienced semantic information. However, irrespective of the type of semantics, blind subjects activate additional extrastriate regions, which are coupled with frontal and temporal semantic regions. The resilience of semantic retrieval responses to visual deprivation suggests a considerable degree of innate and epigenetic specification of the semantic system. In contrast, the exuberant functional connectivity between extrastriate and 'core' semantic retrieval regions might be explained by abnormal pruning processes during early neurodevelopment.

Adult↗
PubMed2001

A four-dimensional approach to medical image retrieval.

Image retrieval is faced with different problems. Few proposed solutions consider the heterogeneity of user competence (e.g. physicians, researchers, students, etc.) and the necessity of a high expressive power for medical image description. This paper presents a solution designed for medical imaging retrieval. It consists of providing a four-dimensional approach able to integrate different views of the medical image, to deal with complex medical queries. Via use of the Spatial Knowledge Model, we propose hybrid (textual and visual) and customizable interfaces, appropriate for non-computer scientist users. Our prototype, accessible through the Web, has been tested by a group of medical students and physicians and gives very satisfactory results.

Computer Graphics↗
PubMed1999

Consultation of medical narratives in the electronic medical record.

This article presents an overview of a research project concerning the consultation of medical narratives in the electronic medical record (EMR). It describes an analysis of user needs, the design and implementation of a prototype EMR system, and the evaluation of the ease of consultation of medical narratives when using this system. In a questionnaire survey, 85 hospital physicians judged the quality of their paper-based medical record with respect to data entry, information retrieval and some other aspects. Participants were more positive about the paper medical record than the literature suggests. They wished to maintain the flexibility of data entry but indicated the need to improve the retrieval of information. A prototype EMR system was developed to facilitate the consultation of medical narratives. These parts were divided into labeled segments that could be arranged source-oriented and problem-oriented. This system was used to evaluate the ease of information retrieval of 24 internists and 12 residents at a teaching hospital when using free-text medical narratives divided at different levels of detail. They solved, without time pressure, some predefined problems concerning three voluminous, inpatient case records. The participants were randomly allocated to a sequence that was balanced by patient case and learning effect. The division of medical narratives affected speed, but not completeness of information retrieval. Progress notes divided into problem-related segments could be consulted 22% faster than when undivided. Medical history and physical examination divided into segments at organ-system level could be consulted 13% faster than when divided into separate questions and observations. These differences were statistically significant. The fastest divisions were also appreciated as the best combination of easy searching and best insight in the patient case. The results of our evaluation study suggest a trade-off between searching and reading: too much detailed segments will delay the consultation of medical narratives. Validation of the results in daily practice is recommended.

Attitude of Health Personnel↗
PubMedDate not supplied

Medical database security evaluation.

Users of medical information systems need confidence in the security of the system they are using. They also need a method to evaluate and compare its security capabilities. Every system has its own requirements for maintaining confidentiality, integrity and availability. In order to meet these requirements a number of security functions must be specified covering areas such as access control, auditing, error recovery, etc. Appropriate confidence in these functions is also required. The 'trust' in trusted computer systems rests on their ability to prove that their secure mechanisms work as advertised and cannot be disabled or diverted. The general framework and requirements for medical database security and a number of parameters of the evaluation problem are presented and discussed. The problem of database security evaluation is then discussed, and a number of specific proposals are presented, based on a number of existing medical database security systems.

Accreditation↗
PubMed1995

Applying a controlled medical terminology to a distributed, production clinical information system.

To maximize the value of computerized medical records systems, an organizing structure is needed. That structure can be provided by a controlled medical terminology (CMT). At Columbia-Presbyterian Medical Center, we have been employing a controlled medical terminology, our Medical Entities Dictionary (MED), to mediate the storage and retrieval of patient data and enable decision support applications. This paper describes how the MED is actually used for data management in our distributed clinical information systems environment. Our system tools which access the MED for production purposes facilitate the mapping of terms from many sources to a uniform representation of concepts and also return information about the relationships between concepts. Applications which access a CMT for production purposes should be optimized for performance in high volume settings, fault tolerant, synchronizable, extensible, portable, and maintainable. We briefly describe our system architecture and then demonstrate how we utilize the MED for translation and semantic information as data is moved into and out of our patient database. We discuss our current tools and present a preview of the next generation of applications which will manage access to the MED for our production systems.

Computer Communication Networks↗
PubMedDate not supplied

Searching for biomedical information on the World Wide Web.

The rapid growth of biomedical information available via the Internet and its most popular retrieval system, the World Wide Web, has fostered active research and development directed toward locating resources that are appropriate for answering specific queries. The goal is to create tools that optimize information retrieval (as measured by two quantities, precision and recall) while minimizing the effort required by the user. Existing Web retrieval tools can be divided into the following groups: manually maintained topical lists; automatically generated word-based indices; software agents and multi-index searching aids; network cataloging methods; and miscellaneous hybrid and newer approaches. Improvements in current methods should arise from further research into: methods of describing objects on the Web; improved ways of searching for (and within) collections of documents as opposed to single documents; the ability to search for fielded documents; and ways to describe resources that span intra- and interdisciplinary as well as cross-cultural linguistic differences. For this last problem, the U.S. National Library of Medicine's Unified Medical Language System (UMLS) will be of great help. As online information retrieval improves, efforts are underway to improve the online information itself; quality control over content is being addressed as the peer-review systems of traditional printed journals migrate into the realm of electronic publication.

Abstracting and Indexing↗
PubMed2005

Validating DICOM content in a remote storage model.

Verifying the integrity of DICOM files transmitted between separate archives (eg, storage service providers, network attached storage, or storage area networks) is of critical importance. The software application described in this article retrieves a specified number of DICOM studies from two different DICOM storage applications; the primary picture archiving and communication system (PACS) and an off-site long-term archive. The system includes a query/retrieve (Q/R) module, storage service class provider (SCP), a DICOM comparison module, and a graphical user interface. The system checks the two studies for DICOM 3.0 compliance and then verifies that the DICOM data elements and pixel data are identical. Discrepancies in the two data sets are recorded with the data elements (tag number, value representation, value length, and value field) and pixel data (pixel value and pixel location) in question. The system can be operated automatically, in batch mode, and manually to meet a wide variety of use cases. We ran this program on a 15% statistical sample of 50,000 studies (7500 studies examined). We found 2 pixel data mismatches (resolved on retransmission) and 831 header element mismatches. We subsequently ran the program against a smaller batch of 1000 studies, identifying no pixel data mismatches and 958 header element mismatches. Although we did not find significant issues in our limited study, given other incidents that we have experienced when moving images between systems, we conclude that it is vital to maintain an ongoing, automatic, systematic validation of DICOM transfers so as to be proactive in preventing possibly catastrophic data loss.

Computer Communication Networks↗
PubMed1999

The strategic and operational characteristics of a distributed phased archive for a multivendor incremental implementation of picture archiving and communications systems.

The long-term (10 years) multimodality distributed phased archive for the Medical Information, Communication and Archive System (MICAS) is being implemented in three phases. The selection process took approximately 10 months. Based on the mandatory archive attributes and desirable features, Cemax-Icon (Fremont, CA) was selected as the vendor. The archive provides for an open-solution allowing incorporation of leading edge, "best of breed" hardware and software and provides maximum flexibility and automation of workflow both within and outside of radiology. The solution selected is media-independent, provides expandable storage capacity, and will provide redundancy and fault tolerance in phase II at minimum cost. Other attributes of the archive include scalable archive strategy, virtual image database with global query, and an object-oriented database. The archive is seamlessly integrated with the radiology information system (RIS) and provides automated fetching and routing, automated study reconciliation using modality worklist manager, clinical reports available at any Digital Imaging and Communications in Medicine (DICOM) workstation, and studies available for interpretation whether validated or not. Within 24 hours after a new study is acquired, four copies will reside within different components of the archive including a copy that can be stored off-site. Phase II of the archive will be installed during 1999 and will include a second Cemax-Icon archive and database using archive manager (AM) Version 4.0 in a second computer room.

Computer Communication Networks↗