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Biomedical subjects

Yaron Denekamp

Publications and source records attributed to Yaron Denekamp.

7 recordsLinked to original sources

Changes in the slope of the first major deflection of the ECG complex during acute coronary occlusion.

To evaluate the effect of acute coronary occlusion (ACO) during percutaneous coronary intervention (PCI) on the slope of the first major deflection of the QRS complex (the initial QRS slope). Standard ECG signals of 18 patients (89 leads), undergoing PCI were recorded prior to and during ACO. The initial QRS slope was calculated in the baseline state and during ACO. Changes in the standard ECG were detected in 36 of 89 leads (40%). The initial QRS slope during ACO was significantly different from baseline in 74 of 89 leads (83%). The specificity of the change in the slope during ACO was low (29%).

Angioplasty, Balloon, Coronary↗

A clinical problem-oriented decision support model based on extended temporal database functionalities.

Several diagnostic decision support systems have been proposed. Yet, such systems are not commonly used partly due to insufficient temporal reasoning. We have developed a clinical problem-oriented diagnostic decision support model that employs temporal reasoning by using extended temporal database functionalities developed at our lab. In addition, our model supports the workflow of the diagnostic process and employs detailed clinical data. We developed a prototype system that implements the concepts of the model.

Databases as Topic↗

A methodology for modular representation of guidelines.

Computer-based clinical practice guidelines often need to be modified when medical knowledge evolves or when guidelines are implemented in a local setting with specific constraints and preferences. To enable easy modifications to guidelines and maintain their integrity, we have developed a methodology for modular representation of guidelines. Using this approach, we create guidelines in a hierarchical and modular manner. We use the Axiomatic Design methodology to facilitate the development of independent modules. Design matrices capture the interactions among modules. The design matrices can be used during guideline modification to create a change process and to enable identification of other modules that are affected by a change to a module. We implemented this modular knowledge representation approach by incorporating it into the Guideline Interchange Format (GLIF) language. We applied this approach to encode parts of three outdated guidelines released during 2000-2001, and we revised these designs to model updated releases of the guideline. Qualitative and quantitative metrics were developed to assess the types of changes made to the encoded guidelines.

Adult↗

Electronic medical record systems in Israel's public hospitals.

BACKGROUND: Various medical centers in Israel have recently incorporated electronic medical record systems. Knowing the EMR systems' features and pattern of use is an essential step for developing locally and nationally integrated systems. OBJECTIVES: To evaluate the status of EMR systems in all major general hospitals in Israel in terms of the applications used and the patterns of use. METHODS: Structured questionnaires were sent to hospital directors and directors of medical informatics units of 26 general and pediatric hospitals serving the vast majority of the population in Israel. The questionnaire included questions pertaining to the EMR systems, their usage, and the attitude of the participants to data security issues. RESULTS: Of the 26 general hospitals 23 (88.4%) returned the questionnaires. Of these, 21 (91.3%) use EMR systems. Twenty-seven different types of systems are in use in Israeli hospitals, and generally more than one type is used in a hospital. Physicians work with EMR systems in over 98% of the departments. Also, the EMR systems are used for clinical admission and discharge in over 90% of the departments and for medical daily follow-up in about 45%. CONCLUSIONS: Most of the hospitals in Israel use EMR systems but there is no standard data model. Physicians are the main users but the amount of data entered is still limited. Adoption of standards is essential for the integration of electronic patient records across Israeli healthcare organizations.

Adolescent↗

A meta-data model for knowledge in decision support systems.

Clinical decision support such as alerts, reminders and guidance are driven by rules often distributed among a variety of applications in a healthcare information system. Due to the increasing size of rule bases, there is a growing need to manage this dispersed knowledge in an integrated environment. A system for management of executable clinical knowledge such as rules should (1) assist in the development and maintenance of rules throughout the rules' life-cycles, (2) support search and retrieval of rules in the knowledge base (e.g., rules for diabetes, rules created by a particular individual), and (3) facilitate the analyses of rules in the knowledge base (e.g., identify rules not updated in the last year). In order to create such a clinical knowledge management system it is necessary to model the meta-data of rules. There have been efforts to document meta-data about rules within the Arden Syntax Medical Logical Modules' project. However, the maintenance and library categories in that project allow mainly free-text information about a rule. We have created a comprehensive meta-data structure and taxonomy for describing clinical rules that supports the features of a knowledge management system. We also tested this model using a representative set of rules.

Artificial Intelligence↗

Applying axiomatic design methodology for guideline revision.

We are investigating the use of axiomatic design (AD) as a principled approach to the revision of guidelines. AD models guidelines in a modular and hierarchical manner and captures interactions be-tween modules. To test this approach we applied AD to encode segments of three guidelines and their revised versions. Guideline encodings for the original versions were modified to incorporate changes made in the revised documents. The results indicate that AD is a promising approach for guideline modeling.

Decision Support Systems, Clinical↗

Evaluation of the phase-plane ECG as a technique for detecting acute coronary occlusion.

OBJECTIVE: To evaluate the phase plane (PP) ECG as a method for detecting acute coronary occlusion (ACO). BACKGROUND: Balloon inflation in a coronary artery during PTCA produces acute myocardial ischemia. The sensitivity of the standard ECG for detecting ACO is approximately 50%, depending on the number of leads recorded. METHODS: The standard ECG signals of 18 patients (91 leads), undergoing PTCA were sampled and converted to digital data, prior to, and during acute coronary occlusion. PPs were constructed by projecting the ECG signals and their first derivatives onto a two-dimensional plane. Standard ECG signals and PPs, prior to ACO, were compared to their respective recordings and PPs during ACO. RESULTS: Using the standard ECG analysis, the acute occlusion was detected in 39 of 91 leads (43%), and in 15 of 18 patients (83%), whereas using the PP analysis it was detected in 82 of 91 leads (90%), and in all 18 patients (100%) (P<0.001, for leads). The median number of leads per patient demonstrating standard ECG changes was 2.0, whereas for the PP analysis it was 5.5 (P<0.001). The specificity of the PP method was 83.5%. CONCLUSIONS: The sensitivity of the PP method for detecting ACO during PTCA was superior to that of the standard ECG analysis. A smaller lead system is required to detect changes of ACO, during PTCA, when the PP method is used. The PP method is simple, low-priced, and may serve to detect acute myocardial ischemia in a number of clinical settings.

Acute Disease↗