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Biomedical subjects

Antoine Geissbuhler

Publications and source records attributed to Antoine Geissbuhler.

18 recordsLinked to original sources
PubMed2004

Experience in implementing inpatient clinical note capture via a provider order entry system.

Care providers' adoption of computer-based health-related documentation ("note capture") tools has been limited, even though such tools have the potential to facilitate information gathering and to promote efficiency of clinical charting. The authors have developed and deployed a computerized note-capture tool that has been made available to end users through a care provider order entry (CPOE) system already in wide use at Vanderbilt. Overall note-capture tool usage between January 1, 1999, and December 31, 2001, increased substantially, both in the number of users and in their frequency of use. This case report is provided as an example of how an existing care provider order entry environment can facilitate clinical end-user adoption of a computer-assisted documentation tool-a concept that may seem counterintuitive to some.

Academic Medical Centers↗
PubMed2004

A reference data set for the evaluation of medical image retrieval systems.

Content-based image retrieval is starting to become an increasingly important factor in medical imaging research and image management systems. Several retrieval systems and methodologies exist and are used in a large variety of applications from automatic labelling of images to diagnostic aid and image classification. Still, it is very hard to compare the performance of these systems as the used databases often contain copyrighted or private images and are thus not interchangeable between research groups, also for patient privacy. Most of the currently used databases for evaluating systems are also fairly small which is partly due to the high cost in obtaining a gold standard or ground truth that is necessary for evaluation. Several large image databases, though without a gold standard, start to be available publicly, for example by the NIH (National Institutes for Health). This article describes the creation of a large medical image database that is used in a teaching file containing more than 8,700 varied medical images. The images are anonymised and can be exchanged free of charge and copyright. Ground truth (a gold standard) has been obtained for a set of 26 images being selected as query topics for content-based query by image example. To reduce the time for the generation of ground truth, pooling methods well known from the text or information retrieval field have been used. Such a database is a good starting point for comparing the current image retrieval systems and to measure the retrieval quality, especially within the context of teaching files, image case databases and the support of teaching. For a comparison of retrieval systems for diagnostic aid, specialised image databases, including the diagnosis and a case description will need to be made available, as well, including gold standards for a proper system evaluation. A first evaluation event for image retrieval is foreseen at the 2004 CLEF conference (Cross Language Evaluation Forum) to compare text-and content-based access mechanism to images.

Databases, Factual↗
PubMed2004

A review of content-based image retrieval systems in medical applications-clinical benefits and future directions.

Content-based visual information retrieval (CBVIR) or content-based image retrieval (CBIR) has been one on the most vivid research areas in the field of computer vision over the last 10 years. The availability of large and steadily growing amounts of visual and multimedia data, and the development of the Internet underline the need to create thematic access methods that offer more than simple text-based queries or requests based on matching exact database fields. Many programs and tools have been developed to formulate and execute queries based on the visual or audio content and to help browsing large multimedia repositories. Still, no general breakthrough has been achieved with respect to large varied databases with documents of differing sorts and with varying characteristics. Answers to many questions with respect to speed, semantic descriptors or objective image interpretations are still unanswered. In the medical field, images, and especially digital images, are produced in ever-increasing quantities and used for diagnostics and therapy. The Radiology Department of the University Hospital of Geneva alone produced more than 12,000 images a day in 2002. The cardiology is currently the second largest producer of digital images, especially with videos of cardiac catheterization ( approximately 1800 exams per year containing almost 2000 images each). The total amount of cardiologic image data produced in the Geneva University Hospital was around 1 TB in 2002. Endoscopic videos can equally produce enormous amounts of data. With digital imaging and communications in medicine (DICOM), a standard for image communication has been set and patient information can be stored with the actual image(s), although still a few problems prevail with respect to the standardization. In several articles, content-based access to medical images for supporting clinical decision-making has been proposed that would ease the management of clinical data and scenarios for the integration of content-based access methods into picture archiving and communication systems (PACS) have been created. This article gives an overview of available literature in the field of content-based access to medical image data and on the technologies used in the field. Section 1 gives an introduction into generic content-based image retrieval and the technologies used. Section 2 explains the propositions for the use of image retrieval in medical practice and the various approaches. Example systems and application areas are described. Section 3 describes the techniques used in the implemented systems, their datasets and evaluations. Section 4 identifies possible clinical benefits of image retrieval systems in clinical practice as well as in research and education. New research directions are being defined that can prove to be useful. This article also identifies explanations to some of the outlined problems in the field as it looks like many propositions for systems are made from the medical domain and research prototypes are developed in computer science departments using medical datasets. Still, there are very few systems that seem to be used in clinical practice. It needs to be stated as well that the goal is not, in general, to replace text-based retrieval methods as they exist at the moment but to complement them with visual search tools.

Databases, Factual↗
PubMed2004

Coping with the variability of medical terms.

OBJECTIVES: To cope with medical terms, which present a high variability of expression through a single natural language, in the sense that any term may be reformulated in hundred of different ways. METHODS: A typology of term variants is presented as a systematic approach in order to favour the implementation of an exhaustive solution. Then, an algorithm able to handle all variants is designed. RESULTS: Using MetaMap, single terms are analyzed with a success rate varying between 68 and 88 %; the algorithm presented in this paper improves this situation. CONCLUSIONS: This experience shows that a semantic driven method, based on a thesaurus, provides a satisfactory solution to the problem of variability of a single term. The presented typology is representative of most variants in a language.

Algorithms↗
PubMed2004

An application of one-class support vector machine to nosocomial infection detection.

Nosocomial infections (NIs)---those acquired in health care settings---are among the major causes of increased mortality among hospitalized patients. They are a significant burden for patients and health authorities alike; it is thus important to monitor and detect them through an effective surveillance system. This paper describes a retrospective analysis of a prevalence survey of NIs done in the Geneva University Hospital. Our goal is to identify patients with one or more NIs on the basis of clinical and other data collected during the survey. In this two-class classification task, the main difficulty lies in the significant imbalance between positive or infected (11%) and negative (89%) cases. To cope with class imbalance, we investigate one-class SVMs which can be trained to distinguish two classes on the basis of examples from a single class (in this case, only "normal" or non infected patients). The infected ones are then identified as "abnormal" cases or outliers that deviate significantly from the normal profile. Experimental results are encouraging: whereas standard 2-class SVMs scored a baseline sensitivity of 50.6% on this problem, the one-class approach increased sensitivity to as much as 92.6%. These results are comparable to those obtained by the authors in a previous study on asymmetrical soft margin SVMs; they suggest that one-class SVMs can provide an effective and efficient way of overcoming data imbalance in classification problems.

Algorithms↗
PubMed2004

User acceptance of clinical information systems: a methodological approach to identify the key dimensions allowing a reliable evaluation framework.

The introduction of Computerized Information Systems (CIS) in clinical settings encountered difficulties. These difficulties highlight the lack of understanding of factors and mechanisms influencing user acceptance. The existing tools and research obtained contradictory results that point out the existence of neglected aspects, such as impacts of CIS, in computer science developments in complex settings. This paper proposes to identify key dimensions which make up user acceptance in clinical settings through the union of three methods. They define five main dimensions which require a concrete evaluation to validate the underlying proposed framework and to complete the description of the acceptance phenomenon. Identifying key dimensions opens the gate to comparative evaluation of many CIS and adds new indicators to evaluate the highlighted dimensions. A long-term aim is the development of longitudinal studies and to state priorities and guidelines for new CIS designs.

Attitude to Computers↗
PubMed2004

Design of a patient-centered, multi-institutional healthcare information network using peer-to-peer communication in a highly distributed architecture.

OBJECTIVE: to design a community healthcare information network for all 450,000 citizen in the State of Geneva, Switzerland, connecting public and private healthcare professionals. Requirements include the decentralized storage of information at the source of its production, the creation of a virtual patient record at the time of the consultation, the control by the patient of the access rights to the information, and the interoperability with other similar networks at the national and european level. METHODS: a participative approach and real-world pilot projects are used to design, test and validate key components of the network, including its technical architecture and the strategy for the management of access rights by the patients. RESULTS: a distributed architecture using peer-to-peer communication of information mediators can implement the various requirements while limiting to an absolute minimum the amount of centralized information. Access control can be managed by the patient with the help of a medical information mediator, the physician of trust.

Community Networks↗
PubMed2003

Building man-man-machine synergies: experiences from the Vanderbilt and Geneva clinical information systems.

OBJECTIVES: To demonstrate how a transition to an open hospital information system architecture can help foster stronger collaborations between computer-based clinical tools and the network of care process stakeholders. METHODS: Description of two evolution strategies towards an open, component-based architecture: the vertical decomposition of a monolithic system, and the transversal integration of foundation components such as terminology servers, documentation management, prescription, scheduling, workflow and notification engines. CONCLUSION: The progressive migration of production clinical systems towards a component-based architecture is feasible at a reasonable cost and leads to substantial benefits in terms of user acceptance through participative design and collaborative maintenance of knowledge bases, as well as improved ability to evolve, scale and share individual components. A taxonomy of the components of a health information system and their interactions should be developed to realize the collaborative potential of a marketplace of interoperable components.

Decision Support Systems, Clinical↗
PubMed2003

XML as standard for communicating in a document-based electronic patient record: a 3 years experiment.

During the past few years, the eXtensible Markup Language (XML) has progressively become a gold standard for accessing, representing and exchanging information, especially in the health care environment. This paper presents an implementation of the use of XML for the electronic patient record (EPR) and discusses more specifically its growing use in two areas of the EPR: first, as a format for the exchange of structured messages, and second, as a comprehensible way of representing patient documents. These statements rely on a 3 years experiment conducted at the Geneva University Hospital as part of its document-centered EPR.

Delivery of Health Care↗
PubMed2003

Integrating content-based visual access methods into a medical case database.

In the computer vision domain, content-based access methods to all forms of multimedia data are a hot research topic. A large number of tools have been developed to find documents in multimedia repositories and to manage the (visual) information that has been created, for example by the Internet. Although no general breakthrough has been achieved with respect to searching diverse databases with automatically extracted features, the techniques have gained acceptance in a few well-defined domains such as image agencies (Corbis) and trademark research. In the medical domain, the number of digital images produced and used for teaching, diagnostics and therapy is rising in a similar way as in other domains. Still, there are only a few image retrieval systems that use automatically extracted visual features for content-based access to medical image databases. This article describes the use of an open source image retrieval system (GIFT) that has been adapted for the use with medical images using the image case database CasImage that has been developed and maintained by the University Hospital of Geneva and that is in routine use. The first results show the potential of this technique to retrieve similar cases from a case database. This is an important task for teaching and might also become important for diagnostics using case-based reasoning, for example. For the use as a diagnostic tool, it is foreseen to specialize the visual features for the domain of lung image retrieval, using high resolution computed tomography (HRCT) images.

Database Management Systems↗
PubMed2003

Nursing care nomenclatures: real implementation in the computerized patient care record.

We report our experience in the conception and the use of a detailed nursing care documentation electronic record. This nursing care record is completely nomenclature driven, including the user-interface. International nomenclatures or classifications such as NANDA are used. They have been translated to French and their language adopted to the local practice habits. This nursing CPR is used in nineteen wards in the five campuses of the University Hospitals of Geneva, covering a broad range of nursing care types, such as acute adult and paediatric care, surgery, general internal medicine, geriatrics, in- and outpatient psychiatry and long-term rehabilitation. This paper focuses on the problematic of the use of nomenclatures and classification in a nursing daily practice, particularly the social and behavioural challenges that had to be faced. The rationale behind the use of these nomenclatures is presented. We present some of the techniques that have been used to make a nomenclature-driven nursing CPR more attractive for nurses.

Documentation↗
PubMed2003

Telemedicine in Western Africa: lessons learned from a pilot project in Mali, perspectives and recommendations.

OBJECTIVE: to evaluate the feasibility, potential and risks of an internet-based telemedicine network in developing countries of Western Africa. METHODS: a project for the development of a national telemedicine network in Mali was initiated in 2001, using internet-based technologies for distance learning and teleconsultations. RESULTS: the telemedicine network has been in productive use for 12 months and has enabled various collaboration channels, including North-South, South-South, and South-North distance learning and teleconsultations. It also unveiled a set of potential problems: a) limited pertinence of North-South collaborations when there are major differences in available resources or socio-cultural contexts between the collaborating parties; b) risk of induced digital divide if the periphery of the health system is not involved in the development of the network, and c) need for the development of local medical contents management skills. CONCLUSION: the identified risks must be taken into account when designing large-scale telemedicine projects in developing countries and can be mitigated by the fostering of South-South collaboration channels, the use of satellite-based internet connectivity in remote areas, and the valorization of local knowledge and its publication on-line.

Africa, Western↗
PubMed2002

Understanding usage patterns of handheld computers in clinical practice.

Handheld computers are commonly used in clinical practice and often considered invaluable by physicians. Though full of promise, the technology is still costly and literature assessing its real use in clinical practice remains scarce. In an effort to better understand how Personal Digital Assistants (PDA) can be utilized as clinical tools, we designed a study that closely monitored the use of a selection of handheld applications by a cohort of interns in a service of Internal Medicine. Information gathered about actual use of the mobile applications offer valuable insights on usage patterns of tools that promise to be become an important part of our clinical practice in the years to come, and will hopefully help guide future developments.

Computers, Handheld↗
PubMed2002

Multilingual approach to ICD10: on the need for a source reference database.

The distribution of ICD10 is of concern for thousand of developers in numerous countries. The absence of some basic features to facilitate the transfer and consequently to augment the quality of the delivered version is a constant characteristic. Errors, ambiguities, missing terms, unrecognised attributes are quite common, despite the efforts of some national centres doing their best to fill this gap. For other countries and languages, where such centres do not exist or do not have sufficient resources, this problem is even stronger. A reference ICD database is clearly a need today. The following features are to be made available out of an ICD database: exact count of terms, whether they are systematic, include, exclude or daggers and asterisks pairs, eventually at chapter level; exact count of notes, references and indirect exclusions; recommended structure of relational tables for ICD representation; basic structure of the classification at any level of detail. These features are somewhat language dependant and should be repeated for each one. This paper demonstrates the benefits of publishing such ICD reference information in order to improve the future ICD tools to be developed in numerous countries.

Database Management Systems↗
PubMed2002

XML as standard for communicating in a document-based electronic patient record: a three years experiment.

During the past few years, the eXtensible Markup Language (XML) has experienced a growing use for accessing, representing and exchanging information, especially in the health care environment. This paper discusses the potentials of the use of XML for the electronic patient record (EPR) in two ways: first, as a format for the exchange of structured messages, and second, as a comprehensible way of representing patient documents. These statements rely on a three years experiment conducted at the Geneva University Hospital as part of its document-centred EPR.

Medical Records Systems, Computerized↗
PubMedDate not supplied

Integration of a multimedia teaching and reference database in a PACS environment.

In one radiology department, a computerized authoring and editing environment was developed and integrated with the picture archiving and communication systems (PACS) for creation of image-based electronic teaching files to replace a collection of printed film images. This multimedia database and authoring environment allows physicians to create reference databases for teaching and research directly from clinical cases being reviewed on PACS diagnostic workstations. The database engine allows users to generate stand-alone CD-ROMs (compact disks, read-only memory) and World Wide Web-based teaching files. The system is fully compliant with the Digital Imaging and Communications in Medicine (DICOM) standard and supports a large number of standard multimedia image file formats. The focus of the development was on convenience and ease of use of a generic system adaptable to all users. The software was integrated on the PACS workstations to allow users to add new cases to the database at any time and anywhere in the department. A pilot system was implemented in clinical operation, with a central server and several client units.

CD-ROM↗
PubMedDate not supplied

Informatics in radiology (infoRAD): benefits of content-based visual data access in radiology.

The field of medicine is often cited as an area for which content-based visual retrieval holds considerable promise. To date, very few visual image retrieval systems have been used in clinical practice; the first applications of image retrieval systems in medicine are currently being developed to complement conventional text-based searches. An image retrieval system was developed and integrated into a radiology teaching file system, and the performance of the retrieval system was evaluated, with use of query topics that represent the teaching database well, against a standard of reference generated by a radiologist. The results of this evaluation indicate that content-based image retrieval has the potential to become an important technology for the field of radiology, not only in research, but in teaching and diagnostics as well. However, acceptance of this technology in the clinical domain will require identification and implementation of clinical applications that use content-based access mechanisms, necessitating close cooperation between medical practitioners and medical computer scientists. Nevertheless, content-based image retrieval has the potential to become an important technology for radiology practice.

Humans↗