Biomedical subjects

W Sujansky

Publications and source records attributed to W Sujansky.

7 recordsLinked to original sources

PubMed1997

Towards improved knowledge sharing: assessment of the HL7 Reference Information Model to support medical logic module queries.

Because clinical databases vary in structure, access methods and vocabulary used to represent data, the Arden Syntax does not define a standard model for querying databases. Consequently, database queries are encoded in ad hoc ways and enclosed in "curly braces" in Medical Logic Modules (MLMs). However, the nonstandard representation of queries impairs sharing of MLMs, an impediment that has come to be known as the "curly braces problem." As a first step in solving this problem, we evaluated the proposed HL7 Reference Information Model (RIM) as a foundation for a standard query model for the Arden Syntax. Specifically, we analyzed the MLM knowledge base at the Columbia-Presbyterian Medical Center and compared the queries in these MLMs to the RIM. We studied 488 queries in 104 MLMs, identifying 674 total query data elements. Laboratory tests accounted for 45.8% of these elements, while demographic and ADT data accounted for 37.6%. Pharmacy orders accounted for 10.5%, medical problems for 4.3% and MLM output messages for 1.6%. We found that the RIM encompasses all but those data elements signifying MLM output (1.6% of the total). We conclude that the majority of queries in the CPMC knowledge base access a relatively small set of data elements and that the RIM encompasses these elements. We propose extensions of this analysis to continue construction of an Arden query model capable of solving the "curly braces problem."

Artificial Intelligence↗

PubMed1996

An evaluation of the TransFER model for sharing clinical decision-support applications.

TransFER is a formal model designed to facilitate the sharing of decision-support applications across institutions with heterogeneous clinical databases. The TransFER model provides a mechanism to automatically customize database queries based on a reference schema of clinical data and an encoded set of database mappings. In this paper, we describe the elements of the TransFER model and we present the results of a formal evaluation we conducted to assess the utility and generality of the model. The results suggest that the TransFER has significant potential for automating query translation and facilitating application sharing, but that further work on the representation of temporal semantics, on the modeling of missing data, and on the optimization of complex queries is required.

Decision Making, Computer-Assisted↗

PubMed1994

Towards a standard query model for sharing decision-support applications.

Many clinical decision-support applications are created in a centralized manner, but distributed widely for local use. When such applications include queries to electronic patient databases, the queries must be translated to conform to local database specifications. Because no well-defined standard model of clinical data exists, the translation process is ad hoc, costly, and error-prone. In this paper, we propose an abstract formalism, called the Standard Query Model Framework, for specifying a standard clinical data model and for supporting the automated and reliable translation of queries that appear in shared decision-support applications. We present the components of this framework, discuss their desirable features, and describe a prototype that we have developed for relational patient databases. We also highlight the outstanding research issues relevant to our approach.

Database Management Systems↗

PubMed1992

The SQLX system: generating explanations for clinical rules encoded in SQL.

We have developed a system to provide case-specific explanations for SQL query results. The explanation facility, called SQLX, is intended to improve user acceptance of clinical rules that are encoded in the SQL query language and are triggered by updates to a relational database. Our design goal is to combine the efficiency and familiarity of the SQL query model with a more intuitive and case-specific display of query results. SQLX defines an augmented SQL syntax that allows the incorporation of explanation text directly into query specifications. A query analyzer determines which retrieved data logically contribute to rule firing, and combines the data with explanation text to generate a case-specific explanation. Although features of the SQL query model limit the use of this method as a general-purpose rule-explanation facility, the current design accommodates a wide range of SQL query formulations and can provide efficient processing and intuitive explanations of many clinical rules.

Anesthesiology↗

PubMed1992

Reuse of knowledge represented in the Arden syntax.

Knowledge Data Systems is building a medical expert system for monitoring clinical events. This system uses the Arden syntax as a knowledge representation. Having encoded may different types of rules in the Arden syntax, we have noticed a number of shortcomings of the syntax. Many of these shortcomings originate from Arden's procedural orientation, from its failure to separate factual medical knowledge from knowledge of how the medical facts should be applied to a particular clinical situation. The absence of this separation leads to redundancy of knowledge and to difficulties in knowledge reuse. We suggest that standards for representing medical logic preserve this separation to engender knowledge reuse. We propose a general framework for representing medical logic which supports both knowledge sharing and reuse.

Diagnosis, Computer-Assisted↗

PubMed1991

Management of complex immunogenetics information using an enhanced relational model.

Flow cytometry has become a technique of paramount importance in the armamentarium of the scientist in such domains as immunogenetics. In the PENGUIN project, we are currently developing the architecture for an expert database system to facilitate the design of flow-cytometry experiments. This paper describes the core of this architecture--a methodology for managing complex biomedical information in an extended relational framework. More specifically, we exploit a semantic data model to enhance relational databases with structuring and manipulation tools that take more domain information into account and provide the user with an appropriate level of abstraction. We present specific applications of the structural model to database schema management, data retrieval and browsing, and integrity maintenance.

Cell Separation↗

PubMed1986

Mast cell "disappearance" in chronic murine graft-vs-host disease (GVHD)-ultrastructural demonstration of "phantom mast cells".

Mast cells were studied during the induction of chronic graft-vs-host disease (GVHD) induced in mice across minor histocompatibility barriers. B10.D2 spleen cells (or control BALB/c cells) were injected into irradiated (600 rad) BALB/c recipients. Serial skin biopsies were taken over 26 days, during which time changes occurred resembling scleroderma, namely, dermal fibrosis, a mononuclear cell infiltrate, and loss of fat and appendages. Mast cells, when stained with toluidine blue, "disappeared" from GVHD, but not from control skin. Ultrastructural analysis showed that mast cells in GVHD skin were indeed present but underwent degranulation. Some mast cells showed only pale expanded sacs, indicating granule depletion. Because these cells could not be seen by toluidine blue staining but were plainly present, we have called them "phantom mast cells." Cellular activation occurred in many GVHD mast cells as shown by increased cytoplasmic activity, with numerous Golgi complexes, ribosomes, granular endoplasmic reticulum, and small vesicles. No identifiable mast cells were seen after day 19. No significant changes were seen in the mast cells of syngeneic control mice. We believe that immunologic processes in chronic GVHD cause a slow release of mast cell granule contents, which is different from anaphylactic degranulation. The depleted mast cells (invisible by toluidine blue staining) are also activated, perhaps in an attempt to replete their stores of granule contents. We discuss the relation of mast cell changes to fibrosis.

Animals↗