Biomedical subjects

Thomas Wetter

Publications and source records attributed to Thomas Wetter.

10 recordsLinked to original sources

PubMed2006

To decay is system: the challenges of keeping a health information system alive.

Health information system (HIS) architecture and socio-technical approaches for system deployment have been topics of systematic research for decades. Sustainable operation in gradually changing environments, however, has not yet received sufficient attention. Even HIS that have gone life to the satisfaction of their developers and end-users may degrade gracefully or fail catastrophically if not continuously and thoroughly kept in sync with their environment. Critical environmental changes may owe their origins to the complexity of health care and its delivery. Seemingly minor environmental changes can result in significant failures on the part of the information system and may adversely affect the quality of health care delivered. Such minor degradation or near failure may go unnoticed for a while and then hit unexpectedly. Five origins of decay will be analyzed. Methods of systematic observation and containment of such decaying processes will tentatively be presented. Some origins of system decay exist in the immediate hospital or regional setting of usage. Indicators to identify processes of decay will be suggested and methods to preemptively reduce the risk of decay will be presented. Other origins span national health care systems or beyond. Not all such risks can hence be controlled locally. Software Oversight Committees may be an instrument to monitor those risks that cannot be controlled through routine local management.

Computer Systems↗

PubMed2005

A similarity measure for case based reasoning modeling with temporal abstraction based on cross-correlation.

Adverse drug events (ADEs) are a major limitation of drug safety. They are often caused by inappropriate selection of dose and the concurrent use of drugs modulating each other (drug interaction). Risk assessment and prevention strategies must therefore consider co-administered drugs, individual doses, and their timing. In a new approach we evaluated the performance of cross correlation, commonly used in signal processing, to determine similarities in patient treatments. To achieve this, patient treatments were modeled as groups of vectors representing discrete time intervals. These vectors were cross-correlated and the results evaluated to find clusters in time courses indicating similarity in treatment of different patients. To evaluate our algorithm, we then created a number of test cases. The focus of this article is on each treatment, and its pattern in time and dosage. The algorithm successfully produces a relatively low similarity score for cases that are completely different with respect to their pattern of time and dosage but high scores when they are equal (score of 0.699) or similar (score of 0.528) in their therapies, and thus succeeds in having a relatively high specificity (27/30). Such an approach might help to considerably reduce the problem of false alarms which hampers most existing alerting systems for medication errors or impending ADEs.

Adverse Drug Reaction Reporting Systems↗

PubMed2005

Minimalist knowledge representation of primary care diseases in the medrapid.info knowledge base.

BACKGROUND: Communication media commonly used in medicine today no longer meet the needs brought on by the present knowledge explosion. The Heidelberg medrapid project has been developed to quickly communicate high-quality clinical knowledge to physicians. METHODS: In this paper, medrapid is introduced as an online clinical knowledge resource, and the methods used by the 'knowledge entry' function for the minimalist representation of clinical knowledge in the knowledge base are discussed. RESULTS: On average, fewer than 1.4 problems per disease arose during the input of the formal representation of clinical knowledge using the 'knowledge entry' function. However, representation of disease time processes, descriptions, warnings and graphics with the 'knowledge entry' function remains problematic. CONCLUSIONS: The 'knowledge entry' function allows fast formal representation of clinical knowledge (<14 minutes per disease) and testing using the integrated quality management system. In the near future, new measures must be found to improve the problematic representation of disease time processes, descriptions, warnings and graphics to formally represent clinical knowledge using the medrapid 'knowledge entry' function.

Germany↗

PubMed2005

The establishment of Bayesian Coronary Artery Disease Prediction model.

This poster will demonstrate how we build up the module of Bayesian Coronary Artery Disease Predicting Evidence-Based Medicine. The system-module may help the young professional understand the effect of factors for referring patients to take the invasive examination of Angiographic.Moreover, the non-invasive information-tech also can perform as the screening tool on a clinical or a community-based epidemiology.

Bayes Theorem↗

PubMed2004

Using the miraEST assembler for reliable and automated mRNA transcript assembly and SNP detection in sequenced ESTs.

We present an EST sequence assembler that specializes in reconstruction of pristine mRNA transcripts, while at the same time detecting and classifying single nucleotide polymorphisms (SNPs) occuring in different variations thereof. The assembler uses iterative multipass strategies centered on high-confidence regions within sequences and has a fallback strategy for using low-confidence regions when needed. It features special functions to assemble high numbers of highly similar sequences without prior masking, an automatic editor that edits and analyzes alignments by inspecting the underlying traces, and detection and classification of sequence properties like SNPs with a high specificity and a sensitivity down to one mutation per sequence. In addition, it includes possibilities to use incorrectly preprocessed sequences, routines to make use of additional sequencing information such as base-error probabilities, template insert sizes, strain information, etc., and functions to detect and resolve possible misassemblies. The assembler is routinely used for such various tasks as mutation detection in different cell types, similarity analysis of transcripts between organisms, and pristine assembly of sequences from various sources for oligo design in clinical microarray experiments.

Animals↗

PubMed2003

Functional classification of proteins using a nearest neighbour algorithm.

With the large volume of genomic data being analysed nowadays it becomes extremely important to provide automated ways of protein classification to give the scientist a good overview of the analysed data. The system described here is very flexible and can be used with any given protein classification scheme. Before using the system, it has to be trained with a set of already classified proteins. Afterwards, other proteins can be classified by the system automatically. Several tests have been performed to assess the quality of this classification; they have shown the usefulness of the system. The system will be available as part of a commercial software package.

Algorithms↗

PubMed2002

Increase in amino acids in the pons after sleep deprivation: a pilot study using proton magnetic resonance spectroscopy.

Total sleep deprivation (TSD) is an efficient method to relieve depression. An involvement of GABAergic and glutamatergic neurotransmission in the pathophysiology of depression and the mechanism of action of TSD has been suggested. To directly assess the content of GABA, glutamate (Glu) and glutamine (Gln) before and after TSD, we estimated their concentrations in four brain regions in six healthy subjects using proton magnetic resonance spectroscopy. The unresolved estimate of GABA, Glu and Gln, as well as GABA and Gln were increased in the pons after 24 h of TSD, the effect being prominent in three subjects. There were no significant changes in the hypothalamus, thalamus or parietooccipital cortex. These preliminary data support earlier animal data and indirect findings in humans suggesting that GABA and Gln, especially in the pontine structures, may play a key role in the mechanism of TSD.

Adult↗

PubMed2002

Rapid generation of a representative ensemble of N-glycan conformations.

Glycosylated proteins are ubiquitous components of extracellular matrices and cellular surfaces where their oligosaccharide moieties are implicated in a wide range of cell-cell and cell-matrix recognition events. Glycans constitute highly flexible molecules. Only a small number of glycan X-ray structures is available for which sufficient electron density for an entire oligosaccharide chain has been observed. An unambiguous structure determination based on NMR-derived geometric constraints alone is often not possible. Time consuming computational approaches such as Monte Carlo calculations and molecular dynamics simulations have been widely used to explore the conformational space accessible to complex carbohydrates. The generation of a comprehensive data base for N-glycan fragments based on long time molecular dynamics simulations is presented. The fragments are chosen in such a way that the effects of branched N-glycan structures are taken into account. The prediction database constitutes the basis of a procedure to generate a complete set of all possible conformations for a given N-glycan. The constructed conformations are ranked according to their energy content. The resulting conformations are in reasonable agreement with experimental data. A web interface has been established (http://www.dkfz.de/spec/glydict/), which enables to input any N-glycan of interest and to receive an ensemble of generated conformations within a few minutes.

Carbohydrate Conformation↗

PubMed2002

Data security and protection in cross-institutional electronic patient records.

This paper describes data protection and data security requirements of a cross-institutional electronic patient record, and presents possible solutions for meeting these requirements. A comprehensive analysis of literature and legal documents was performed. Beside the general requirements that the EPR of a single institution must meet, specific requirements exist for cross-institutional EPRs. In Germany, patient information may only be revealed to external physicians within so-called "treatment connections". A secure connection between the EPR-systems of two health institutions in Germany, which jointly treat tumor patients, was established using additional SecuRemote Software. The development and implementation of a cross-institutional EPR is a complicated process, mainly due to data security regulations. However, its introduction is thought to be valuable, since a cross-institutional EPR will improve communication within shared care processes, and, thus, improve the quality of patient care.

Computer Security↗

PubMed2002

Supporting clinical practice guidelines: lifecycle of guidelines for oncology within an XML-based guideline framework.

Clinical Practice Guidelines (CPGs) have become important instruments for supporting patient care. Many structure models for CPGs have been developed to explicitly gain structured CPG documents, some of them using XML. Often, however, problems arise in filling these structures with content and integrating CPG applications into an EPR/HIS The Universities of Giessen and Heidelberg have each presented an XML-based CPG structure, which are actually being merged into one. The obtained CPG structure will build our common "xCPG core model" embedded in an "XML framework", an authoring environment. This paper shows how this model used in the framework could support the entire 5-step CPG lifecycle, spanning CPG development, the integration of a CPG into an EPR/HIS, as well as maintenance. Furthermore, this paper points out how the method draws on the different information management services as a precondition for successful CPG implementation.

Medical Oncology↗