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Results for “Knowledge base”

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PubMedDate not supplied

A knowledge-based approach to deconvolve the water component in in vivo proton MR spectroscopy.

OBJECTIVE: The water component dominates in in vivo proton (1H) spectroscopy. This consists of a prominent central peak with large "wings," and consequently metabolites that lie on the "wings" become difficult to quantitate. A method has been developed to deconvolve the water component in in vivo 1H spectroscopy, hence highlighting the metabolite information. MATERIALS AND METHODS: Spectra were acquired from volunteers and patients using 4D chemical shift imaging. The water deconvolution procedure employed knowledge-based data processing in the frequency domain and was fully automated. This involved describing the water component as a coarse function consisting of a "bulk" region and "wing" areas. Points were identified in the spectrum that fit this description and then linked together to produce the water component. The latter was smoothed and then subtracted from the original spectra to produce good water deconvolution. RESULTS: Over 2,000 in vivo 1H spectra have been subjected to this algorithm. The method took approximately 5 s to execute per spectrum consisting of 2,048 data points. CONCLUSION: Knowledge-based data processing has provided a fast, efficient, and robust procedure to deconvolve the water component.

Adult↗

PubMed1989

Knowledge-based approach to sleep EEG analysis--a feasibility study.

A knowledge-based approach to automated sleep EEG (electroencephalogram) analysis is described. In this system, an object-oriented approach is followed in which specific waveforms and sleep stages ("objects") are represented in terms of frames. The latter capture the morphological and spatio-temporal information for each object. An object detection module ("frame matcher"), operating on the frames, is employed to identify what features need to be extracted from the EEG and to trigger the appropriate "specialist"--specialized signal processing modules--to obtain values for these features. This leads to an opportunistic approach to EEG interpretation with quantitative information being extracted from the signal only when needed by the reasoning processes. The system has been tested on the detection of K complexes and sleep spindles. Its performance indicates that the approach followed is feasible and can become a powerful tool for automated EEG interpretation.

Electroencephalography↗

PubMed1989

ESPRE: a knowledge-based system to support platelet transfusion decisions.

ESPRE is a knowledge-based system which aids in the review of requests for platelet transfusions in the hospital blood bank. It is a microcomputer-based decision support system written in LISP and utilizes a hybrid frame and rule architecture. By automatically obtaining most of the required patient data directly from the hospital's main laboratory computers via a direct link, very little keyboard entry is required. Assessment of time trends computed from the data constitutes an important aspect of this system. To aid the blood bank personnel in deciding on the appropriateness of the requested transfusion, the system provides an explanatory report which includes a list of patient-specific data, a list of the conditions for which a transfusion would be appropriate for the particular patient (given the clinical condition), and the conclusions drawn by the system. In an early clinical evaluation of ESPRE, out of a random sample of 75 platelet transfusion requests, there were only three disagreements between ESPRE and blood bank personnel.

Decision Support Techniques↗

PubMed2000

Integrating knowledge based functionality in commercial hospital information systems.

Successful integration of knowledge-based functions in the electronic patient record depends on direct and context-sensitive accessibility and availability to clinicians and must suit their workflow. In this paper we describe an exemplary integration of an existing standalone scoring system for acute abdominal pain into two different commercial hospital information systems using Java/Corba technolgy.

Abdomen, Acute↗

PubMed1995

Modeling drug information for a prescription-oriented knowledge base on drugs.

There exists little theoretical analysis how to represent knowledge on drugs required for computerized drug-prescription applications. A work package drug information modeling is described which was part of the European OPADE project. We describe the content and structure of a Drug Knowledge Base (DKB) designed to meet the requirements of decision-support systems in the domain of drug therapy, and to facilitate data transfer from various information sources. The definition of the DKB content is derived from the analysis of information requirements at the various stages of the process of the clinical usage of drugs (prescribing, administration, and follow-up). The DKB structure results from the classification of the various data items along two dimensions: (1) entities in the pharmaco-therapeutic domain for which information must be defined (the PharmacoTherapeutic Group, the Component, the ManufacturedPreparation, and the Presentation), and (2) the validity score of the pharmaco-therapeutic information (international, national, or local).

Drug Administration Schedule↗

PubMed1998

Distributed cognition and knowledge-based controlled medical terminologies.

Controlled medical terminologies (CMTs) are playing central roles in clinical information systems and medical knowledge resource applications. As these terminologies grow, they are able to support more complex tasks but require more intensive efforts to create and maintain them. Several terminologies are evolving into knowledge bases of medical concepts. The knowledge they include is being used to support distributed cognition in two forms: complex medical decisions involving multiple people and applications, and coordination of maintenance of the terminologies themselves.

Artificial Intelligence↗

PubMed1998

The use of a computerized brain atlas to support knowledge-based training in radiology.

Trainers of radiologists face the particular challenges of teaching normal and abnormal appearance for a variety of imaging modalities, providing access to a large appropriately-indexed case library, and teaching a consistent approach to the reporting of cases. The computer has the potential to address these issues, to supplement conventional teaching of radiology by providing case-based tutoring and diagnostic support based on a large library of images of normal and abnormal anatomy, described in a consistent terminology. The paper presents a new approach to computer-based training in radiology that combines a knowledge-based tutor with an on-line medical atlas. It describes two existing computer systems, the MR Tutor and ATLAS, and discusses the medical, computational, epistemic, and pedagogic issues involved in developing a combined Atlas-Tutor. Integrating an atlas with a training system could significantly improve the teaching and support offered, but practical difficulties include the need to merge knowledge representations and to incorporate techniques for registering atlas plates on images that exhibit abnormalities. The paper addresses these problems, and concludes by indicating how the Atlas-Tutor might be employed in practical radiology training.

Atlases as Topic↗

PubMed1991

Knowledge-based computer system to aid in the histopathological diagnosis of breast disease.

A knowledge-based computer system, designed to assist pathologists in the histological diagnosis of breast disease, is described. This system represents knowledge in the form of "disease profiles" and uses a novel inference model based on the mathematical technique of hypergraphs. Its design overcomes many of the limitations of existing expert system technologies when applied to breast disease. In particular, the system can quickly focus on a differential problem and thus reduce the amount of data necessary to reach a conclusion. The system was tested on two sets of samples, consisting of 14 retrospective cases and five hypothetical cases of breast disease. Its recommendations were judged "correct" by the evaluating pathologist in 15 cases. This study shows the feasibility of providing "decision support" in histopathology.

Breast↗

PubMed1999

Contour tracking using a knowledge-based snake algorithm to construct three-dimensional pharyngeal bolus movement.

Videofluorography (VFG) using a barium-mixed bolus is in wide clinical use for assessing patients with swallowing disorders. VFG is usually done with both lateral (LA) and anterior-posterior (AP) views, most commonly in two separate sittings. A real-time, three-dimensional (3-D) representation of the evolution of a pharyngeal bolus and its volumetric information can potentially help clinicians analyze and visualize the kinematics of swallowing, dysphagia, and compensatory therapeutic strategies. Active contour models, also known as "Snakes," have been used to solve various image analysis and computer vision problems. We applied a Snake algorithm to automate in part the contour tracking and reconstruction of VFG images to visualize and quantitatively analyze the 3-D evolution of a pharyngeal bolus. To improve the accuracy of the Snake search, we provided the additional "knowledge" of the pharyngeal image itself, which served as an extra constraint to push the Snake curve toward the desired contour. VFG of pharyngeal bolus transport in a normal subject was recorded by using barium-mixed boluses (viscosity: 185 centipoise, density: 2.84 g/cc) with volumes of 5, 10, and 20 ml. The resulting LA and AP video images were digitally captured and matched frame by frame. The knowledge-based Snake search algorithm was used to generate Snake points to satisfy both internal (i.e., smoothness) and external (i.e., boundary fitting) constraints. Using these Snake points, we traced the 3-D bolus movement at each time instant, assuming elliptic geometry in the cross-section of the pharyngeal bolus. By concentrating the 3-D images for each time instant, we developed a 3-D movie representing pharyngeal bolus movement. The efficiency, reproducibility, and accuracy of this algorithm in tracing pharyngeal bolus boundaries and estimating front/tail velocities were assessed and found satisfactory. We conclude that 3-D pharyngeal bolus movement can be traced both accurately and efficiently by using a knowledge-based Snake search algorithm.

Algorithms↗

PubMed2005

Partitioning knowledge bases between advanced notification and clinical decision support systems.

Due to the varying rates of change of ephemeral administrative and enduring clinical knowledge in decision support systems (DSSs), the functional partition of knowledge base (KB) components can lead to more efficient and cost-effective system implementation and maintenance. Our prototype loosely couples a clinical event monitor developed by Columbia University Medical Center (CUMC) with a secure notification service proxy developed by IBM Research to form a novel and complex clinical event communication service.

Computer Security↗

PubMed1998

Understanding coronary artery movement: a knowledge-based approach.

The aim of this paper is to describe a knowledge-based system that interprets three-dimensional (3D) coronary artery movement, using data from digital subtraction angiography image sequences. Dynamic information obtained from artery centerline 3D reconstruction and optical flow estimation, is classified according to experimental evidence indicating that artery displacements are quasi-homogeneous by a segment analysis. Characteristic motion features like displacement direction, perpendicular/radial components, rotation direction, curvature and torsion are qualitatively described from an image sequence using symbolic labels. These facts are then related and interpreted using anatomical-functional knowledge provided by a specialist, as well as spatial and temporal knowledge, applying spatio-temporal reasoning schemes. Facts, knowledge and reasoning rules are stated in a declarative form. Detailed examples of local and global interpretation results, using a real reconstructed angiographic biplane image sequence are presented in order to illustrate how our system suitably interprets coronary artery dynamic behavior.

Angiography, Digital Subtraction↗

PubMed1995

Frozen section consultation. Utilization patterns and knowledge base of surgical faculty at a university hospital.

The authors studied the knowledge base of surgical faculty concerning frozen section consultations at a university hospital to determine whether it had any relationship to the appropriateness of frozen section requests. To accomplish this, the reasons for performing frozen sections during a 3-month period were analyzed, and those request that seemed ambiguous or inappropriate were identified. Simultaneously a 15-item questionnaire was distributed to faculty and housestaff dealing with factual information concerning the technique and limitations of frozen section diagnosis (Questions 1-8), as well as appropriateness of frozen section requests in a number of clinical situations (Questions 9-15). The collective score on items of general information (Questions 1-8) was 69%, whereas scores on Questions 9-15 ranged from 39% on the gynecologic question related to evaluation of a cystic ovarian mass to 81% on the general surgery question regarding evaluation of a soft tissue mass. Of 914 frozen sections, 95% were performed for appropriate reasons, which included evaluation of margins (46%), establishing a primary diagnosis (43%), determining adequacy or viability of tissue (3%), or satisfying immediate patient/family concerns ( < 1%). Five percent of frozen sections were performed for ambiguous or seemingly inappropriate reasons. Because fewer than five faculty members were responsible for the inappropriate frozen section request, the authors did not find that the results of the questionnaire predicted or anticipated situations in which inappropriate requests occurred. Nonetheless, the results of the questionnaire indicate there is important general information concerning frozen sections that is not uniformly shared by surgical faculty, such as the types of tissue that cannot be cut on a cryostat, the reasons for deferred frozen sections, and the situations in which fresh tissue is needed for special studies. The authors suggest the inappropriate frozen section could be diminished by an educational initiative targeted at a relatively small segment of clinical faculty, whereas enhancement of general information regarding frozen section should ideally occur in the broader context of clinical conferences using illustrative case material.

Faculty↗

PubMed2002

HepatoConsult: a knowledge-based second opinion and documentation system.

HepatoConsult is a publicly available knowledge-based second opinion and documentation system aiding in the diagnosis of liver diseases. The positive results of a prospective diagnostic evaluation study encouraged its use in clinical routine, although the available hardware infrastructure was not optimal. The comments of the physicians who used the system confirmed the results of the study and showed that the time for data entering is acceptable and the implicit standardization of terminology and documentation is welcome. Suggestions for improvement included the interface to enter data more easily, the scope to be usable for more patients and the additional capability to generate medical reports from the data.

Artificial Intelligence↗

PubMed1997

Automatic construction of knowledge base from biological papers.

We designed a system that acquires domain specific knowledge from human written biological papers, and we call this system IFBP (Information Finding from Biological Papers). IFBP is divided into three phases, Information Retrieval (IR), Information Extraction (IE) and Dictionary Construction (DC). We propose a query modification method using automatically constructed thesaurus for IR and a statistical keyword prediction method for IE. A dictionary of domain specific terms, which is one of the central knowledge sources for the task of knowledge acquisition, is also constructed automatically in the DC phase. IFBP is currently used for constructing the Transcription Factor DataBase (TFDB) and shows good performance. Since the model of knowledge base construction that is adopted into IFBP is carried out entirely automatically, this system can be easily ported across domains.

Algorithms↗

PubMed1997

Cross-institutional reuse of a problem statement knowledge base.

This article describes client and server applications for a problem statement knowledge base derived from a large corpus of provider entered terminology. The current status and potential for integration of the server into the Vanderbilt University Medical Center computing environment are discussed. Finally, an experiment in multiple dimensions of reuse for problem list terms is introduced, and possible strategies to mediate between free text and coded data are examined.

Artificial Intelligence↗

PubMed2002

Ontology development for a pharmacogenetics knowledge base.

Research directed toward discovering how genetic factors influence a patient's response to drugs requires coordination of data produced from laboratory experiments, computational methods, and clinical studies. A public repository of pharmacogenetic data should accelerate progress in the field of pharmacogenetics by organizing and disseminating public datasets. We are developing a pharmacogenetics knowledge base (PharmGKB) to support the storage and retrieval of both experimental data and conceptual knowledge. PharmGKB is an Internet-based resource that integrates complex biological, pharmacological, and clinical data in such a way that researchers can submit their data and users can retrieve information to investigate genotype-phenotype correlations. Successful management of the names, meaning, and organization of concepts used within the system is crucial. We have selected a frame-based knowledge-representation system for development of an ontology of concepts and relationships that represent the domain and that permit storage of experimental data. Preliminary experience shows that the ontology we have developed for gene-sequence data allows us to accept, store, and query data submissions.

Antineoplastic Agents↗

PubMed1993

Knowledge-based design of removable partial dentures using direct manipulation and critiquing.

A knowledge-based system for designing removable partial dentures is described in which graphical representations of denture components are manipulated directly by the user to build the required denture design. The arch form of individual patients may be depicted by linear movement and rotation of the icons representing teeth. The size, shape and position of many denture components are determined dynamically to conform to the shape of abutment teeth and to the juxtaposition of other elements. Expert clinical knowledge is used to analyse the developing design and suggest alternate approaches.

Computer-Aided Design↗

PubMed2004

A fuzzy knowledge-based decision support system for groundwater pollution risk evaluation.

In this paper we propose a decision support system that can provide information on the environmental impact of anthropic activities by examining their effects on groundwater quality. We use the combined value of both intrinsic vulnerability of a specific local aquifer, obtained by implementing a parametric managerial model (SINTACS), and a degree of hazard value, which takes into account specific human activities. Incomplete information is notoriously common in environmental planning. To overcome this deficiency we apply an algorithmic and a qualitative approach, based on expert judgment incorporated into the system's knowledge base. The decision support system takes into account the uncertainty of the environmental domain by using fuzzy logic and evaluates the reliability of the results according to information availability.

Algorithms↗