Modeling Clinical Guidelines for an Epilepsy-CDSS: The EDiTh Project.

The knowledge transformation process involves the guideline for the diagnosis and therapy of epilepsy to an executable and computable knowledge base that serves as the basis for a decision-support system. We present a transparent knowledge representation model which facilitates technical implementation and verification. Knowledge is represented in a plain table, used in the frontend code of the software where simple reasoning is performed. The simple structure is sufficient and comprehensible also for non-technical persons (i.e., clinicians).

Dimer Coupling Energies of the Si(001) Surface.

The coupling energies between the buckled dimers of the Si(001) surface were determined through analysis of the anisotropic critical behavior of its order-disorder phase transition. Spot profiles in high-resolution low-energy electron diffraction as a function of temperature were analyzed within the framework of the anisotropic two-dimensional Ising model. The validity of this approach is justified by the large ratio of correlation lengths, ξ_{∥}^{+}/ξ_{⊥}^{+}=5.2 of the fluctuating c(4×2) domains above the critical temperature T_{c}=(190.6±10) K. We obtain effective couplings J_{∥}=(-24.9±1.3) meV along the dimer rows and J_{⊥}=(-0.8±0.1) meV across the dimer rows, i.e., antiferromagneticlike coupling of the dimers with c(4×2) symmetry.

System for Context-Specific Visualization of Clinical Practice Guidelines (GuLiNav): Concept and Software Implementation.

BACKGROUND: Clinical decision support systems often adopt and operationalize existing clinical practice guidelines leading to higher guideline availability, increased guideline adherence, and data integration. Most of these systems use an internal state-based model of a clinical practice guideline to derive recommendations but do not provide the user with comprehensive insight into the model. OBJECTIVE: Here we present a novel approach based on dynamic guideline visualization that incorporates the individual patient's current treatment context. METHODS: We derived multiple requirements to be fulfilled by such an enhanced guideline visualization. Using business process and model notation as the representation format for computer-interpretable guidelines, a combination of graph-based representation and logical inferences is adopted for guideline processing. A context-specific guideline visualization is inferred using a business rules engine. RESULTS: We implemented and piloted an algorithmic approach for guideline interpretation and processing. As a result of this interpretation, a context-specific guideline is derived and visualized. Our implementation can be used as a software library but also provides a representational state transfer interface. Spring, Camunda, and Drools served as the main frameworks for implementation. A formative usability evaluation of a demonstrator tool that uses the visualization yielded high acceptance among clinicians. CONCLUSIONS: The novel guideline processing and visualization concept proved to be technically feasible. The approach addresses known problems of guideline-based clinical decision support systems. Further research is necessary to evaluate the applicability of the approach in specific medical use cases.

Violation of Boltzmann Equipartition Theorem in Angular Phonon Phase Space Slows down Nanoscale Heat Transfer in Ultrathin Heterofilms.

Heat transfer through heterointerfaces is intrinsically hampered by a thermal boundary resistance originating from the discontinuity of the elastic properties. Here, we show that with shrinking dimensions the heat flow from an ultrathin epitaxial film through atomically flat interfaces into a single crystalline substrate is significantly reduced due to violation of Boltzmann equipartition theorem in the angular phonon phase space. For films thinner than the phonons mean free path, we find phonons trapped in the film by total internal reflection, thus suppressing heat transfer. Repopulation of those phonon states, which can escape the film through the interface by transmission and refraction, becomes the bottleneck for cooling. The resulting nonequipartition in the angular phonon phase space slows down the cooling by more than a factor of 2 compared to films governed by phonons diffuse scattering. These allow tailoring of the thermal interface conductance via manipulation of the interface.

Hospital-wide ELectronic medical record evaluated computerised decision support system to improve outcomes of Patients with staphylococcal bloodstream infection (HELP): study protocol for a multicentre stepped-wedge cluster randomised trial.

INTRODUCTION: Staphylococci are the most commonly identified pathogens in bloodstream infections. Identification of Staphylococcus aureus in blood culture (SAB) requires a prompt and adequate clinical management. The detection of coagulase-negative staphylococci (CoNS), however, corresponds to contamination in about 75% of the cases. Nevertheless, antibiotic therapy is often initiated, which contributes to the risk of drug-related side effects. We developed a computerised clinical decision support system (HELP-CDSS) that assists physicians with an appropriate management of patients with Staphylococcus bacteraemia. The CDSS is evaluated using data of the Data Integration Centers (DIC) established at each clinic. DICs transform heterogeneous primary clinical data into an interoperable format, and the HELP-CDSS displays information according to current best evidence in bacteraemia treatment. The overall aim of the HELP-CDSS is a safe but more efficient allocation of infectious diseases specialists and an improved adherence to established guidelines in the treatment of SAB. METHODS AND ANALYSIS: The study is conducted at five German university hospitals and is designed as a stepped-wedge cluster randomised trial. Over the duration of 18 months, 135 wards will change from a control period to the intervention period in a randomised stepwise sequence. The coprimary outcomes are hospital mortality for all patients to establish safety, the 90-day disease reoccurrence-free survival for patients with SAB and the cumulative vancomycin use for patients with CoNS bacteraemia. We will use a closed, hierarchical testing procedure and generalised linear mixed modelling to test for non-inferiority of the CDSS regarding hospital mortality and 90-day disease reoccurrence-free survival and for superiority of the HELP-CDSS regarding cumulative vancomycin use. ETHICS AND DISSEMINATION: The study is approved by the ethics committee of Jena University Hospital and will start at each centre after local approval. Results will be published in a peer-reviewed journal and presented at scientific conferences. TRIAL REGISTRATION NUMBER: DRKS00014320.

Separating Procedures and Criteria in Computerized Clinical Guidelines - A 3-Layer Approach.

Computerized guidelines have been utilized for several decades by now. Systems based on computerized-guidelines often intertwine (1) medical knowledge representation, (2) guideline procedures and (3) hospital workflows. This induces several drawbacks. Most prominent problems include non-shareability of the computerized guideline between hospitals, limited accessibility of the computerized guideline for humans, and an unclear, often confusing combination of hospital-specific workflow and guideline-induced control flows. This article proposes a 3-layer modelling approach strictly distinguishing the aforementioned three aspects to overcome the respective problems. We applied the 3-layer approach to the implementation of a guideline-interpreting software module in the context of the Medical Informatics Initiative Germany (here: SMITH Project) and comment on the resulting implications for the software design of that module.