Biomedical subjects

Dongwen Wang

Publications and source records attributed to Dongwen Wang.

12 recordsLinked to original sources

PubMed2005

Experimental study of excitability and autorhthmicity in urinary bladder detrusor of diabetes rats.

The changes in excitability and autorhthmicity of bladder detrusor in experimental non-insulin dependent diabetes mellitus (NIDDM) rats were observed. Sixty-nine NIDDM rats as NIDDM group and 69 normal rats as control group were enrolled into this experimental study. At 6th, 10th, 14th, 18th, 22nd and 26th week after the rats were injected last time, the changes in the excitability and autorhthmicity of detrusor strips in vitro were observed. The results showed that the threshold of the tension which made the detrusor strips contract was significantly higher in NIDDM group (0.716 +/- 0.325 g) than in control group (0.323 +/- 0.177 g) (F = 59.63, P < 0.001). At different stages, the threshold of the tension resulting the contract of the detrusor strips in NIDDM group was also higher than in control group. At 18th week after STZ injection, the frequency of spontaneous contract of the detrusor strips in NIDDM was significantly higher than in control group (P < 0.05), whereas at 22nd week, that in NIDDM group was significantly lower than in control group (P < 0.05). It was concluded that the decreased excitability of the bladder detrusor was the earliest and most obvious changes in bladder function in diabetes rats and the autorhthmicity had also changed at the early stage of diabetic bladder.

Animals↗

PubMed2005

Identifying reasoning strategies in medical decision making: a methodological guide.

Reasoning strategies are a key component in many medical tasks, including decision making, clinical problem solving, and understanding of medical texts. Identification of reasoning strategies used by clinicians may prove critical to the optimal design of decision support systems. This paper presents a formal method of cognitive-semantic analysis for the identification and characterization of reasoning strategies deployed in medical tasks and demonstrates its use through specific examples. Although semantic analysis was originally developed in the investigation of knowledge structures, it can also be applied to identify the reasoning and decision processes used by physicians and medical trainees in clinical tasks. Assumptions underlying the methods, as well as illustrations of their use in diagnostic explanation tasks, are presented. We discuss semantic analysis in the context of the current interests in developing medical ontologies and argue that a frame-based propositional analytic methodology can provide a systematic way of addressing the construction of such ontologies. Although the application of propositional analysis methods has some limitations, we show how such limitations are being addressed and present some examples of information tools that have been developed to ease, and make more systematic, the process of analysis.

Artificial Intelligence↗

PubMed2004

GLIF3: a representation format for sharable computer-interpretable clinical practice guidelines.

The Guideline Interchange Format (GLIF) is a model for representation of sharable computer-interpretable guidelines. The current version of GLIF (GLIF3) is a substantial update and enhancement of the model since the previous version (GLIF2). GLIF3 enables encoding of a guideline at three levels: a conceptual flowchart, a computable specification that can be verified for logical consistency and completeness, and an implementable specification that is intended to be incorporated into particular institutional information systems. The representation has been tested on a wide variety of guidelines that are typical of the range of guidelines in clinical use. It builds upon GLIF2 by adding several constructs that enable interpretation of encoded guidelines in computer-based decision-support systems. GLIF3 leverages standards being developed in Health Level 7 in order to allow integration of guidelines with clinical information systems. The GLIF3 specification consists of an extensible object-oriented model and a structured syntax based on the resource description framework (RDF). Empirical validation of the ability to generate appropriate recommendations using GLIF3 has been tested by executing encoded guidelines against actual patient data. GLIF3 is accordingly ready for broader experimentation and prototype use by organizations that wish to evaluate its ability to capture the logic of clinical guidelines, to implement them in clinical systems, and thereby to provide integrated decision support to assist clinicians.

Artificial Intelligence↗

PubMed2004

Design and implementation of the GLIF3 guideline execution engine.

We have developed the GLIF3 Guideline Execution Engine (GLEE) as a tool for executing guidelines encoded in the GLIF3 format. In addition to serving as an interface to the GLIF3 guideline representation model to support the specified functions, GLEE provides defined interfaces to electronic medical records (EMRs) and other clinical applications to facilitate its integration with the clinical information system at a local institution. The execution model of GLEE takes the "system suggests, user controls" approach. A tracing system is used to record an individual patient's state when a guideline is applied to that patient. GLEE can also support an event-driven execution model once it is linked to the clinical event monitor in a local environment. Evaluation has shown that GLEE can be used effectively for proper execution of guidelines encoded in the GLIF3 format. When using it to execute each guideline in the evaluation, GLEE's performance duplicated that of the reference systems implementing the same guideline but taking different approaches. The execution flexibility and generality provided by GLEE, and its integration with a local environment, need to be further evaluated in clinical settings. Integration of GLEE with a specific event-monitoring and order-entry environment is the next step of our work to demonstrate its use for clinical decision support. Potential uses of GLEE also include quality assurance, guideline development, and medical education.

Database Management Systems↗

PubMed2004

Translating Arden MlMs into GLIF guidelines--a case study of hyperkalemia patient screening.

To re-examine the validity of the medical knowledge that are embedded in the legacy system, we translated a Medical Logic Module (MLM) for hyperkalemia patient screening into the GuideLine Interchange Format (GLIF). We used a set of guiding principles to direct the translation. In addition, we used the GLIF3 Guideline Execution Engine (GLEE) as a testing tool to validate the encoded GLIF guideline by applying it to 5 simulated patient cases. The result has shown that it is possible to translate Arden MLMs into GLIF guidelines. However, significant efforts are necessary to handle the problems arose during the translation process. Automatic translation could be a more generalizable approach for future work.

Computer Simulation↗

PubMed2004

[Analysis of the diagnostic criteria of bladder outlet obstruction in benign prostatic hyperplasia].

OBJECTIVE: To analyze the value of the diagnostic criteria for bladder outlet obstruction in benign prostatic hyperplasia (BPH). METHODS: A total of 358 patients with BPH were divided into 3 grades according to fibrous urethrocystoscopy information on the severity of obstructions, which were classified as Grade 1 (slight), Grade 2 (moderate), and Grade 3 (severe). By Schäfer's graph they were divided into 7 grades, represented by 0 to VI. We analyzed the volume of prostate, maximum flow rate (Qmax), residual urine volume, International Prostatic Symptom Score (IPSS) and detrusor instability. Statistical analysis ANOVA (analysis of variance) was made, spearman correlation evaluated and the coefficient of determination measured. RESULTS: Of all the patients, 27 were classified as Grade 1, 236 as Grade 2 and 95 as Grade 3. Eighty-four patients had detrusor instability. The volumes of the prostate ranged from 16 ml to 145 ml, averaging (47.04 +/- 15.61) ml. The mean maximum flow rate was (10.02 +/- 2.12) ml/min and the mean residual urine volume was (84.06 +/- 36.50) ml. With the increase of the severity of obstruction, the volume of the prostate increased (F = 4.216, P < 0.05), IPSS rose (F = 8.408, P < 0.001), the maximum flow rate decreased (F = 22.43, P < 0.001), the residual urine volume rose (F = 163.232, P < 0.001), the incidence of detrusor instability increased (F = 23.637, P < 0.001) and Schäfer's grades were elevated (F = 202.897, P < 0.001). The volume of the prostate, the maximum flow rate (Qmax), residual urine volume, IPSS detrusor instability and Schäfer's grades were all correlated significantly with the severity of the obstruction. The correlation index and coefficient of determination were r = 0.29, R2 = 0.08; r = 0.35, R2 = 0.12; r = -0.69, R2 = 0.47; r = 0.60, R2 = 0.36; r = 0.33, R2 = 0.11; r = 0.72, R2 = 0.52; respectively. The correlation between the urethrocystoscopy information and Schäfer's graph on the severity of the obstruction were the best criteria of all. CONCLUSION: The severity of the obstruction at urethrocystoscopy correlates well with that at urodynamic investigation. Such criteria could improve the sensitivity and specificity of the diagnosis of bladder outlet obstruction.

Aged↗

PubMed2003

The InterMed approach to sharable computer-interpretable guidelines: a review.

InterMed is a collaboration among research groups from Stanford, Harvard, and Columbia Universities. The primary goal of InterMed has been to develop a sharable language that could serve as a standard for modeling computer-interpretable guidelines (CIGs). This language, called GuideLine Interchange Format (GLIF), has been developed in a collaborative manner and in an open process that has welcomed input from the larger community. The goals and experiences of the InterMed project and lessons that the authors have learned may contribute to the work of other researchers who are developing medical knowledge-based tools. The lessons described include (1) a work process for multi-institutional research and development that considers different viewpoints, (2) an evolutionary lifecycle process for developing medical knowledge representation formats, (3) the role of cognitive methodology to evaluate and assist in the evolutionary development process, (4) development of an architecture and (5) design principles for sharable medical knowledge representation formats, and (6) a process for standardization of a CIG modeling language.

Computer Systems↗

PubMed2003

GESDOR - a generic execution model for sharing of computer-interpretable clinical practice guidelines.

We developed the Guideline Execution by Semantic Decomposition of Representation (GESDOR) model to share guidelines encoded in different formats at the execution level. For this purpose, we extracted a set of generalized guideline execution tasks from the existing guideline representation models. We then created the mappings between specific guideline representation models and the set of the common guideline execution tasks. Finally, we developed a generic task-scheduling model to harmonize the existing approaches to guideline task scheduling. The evaluation has shown that the GESDOR model can be used for the effective execution of guidelines encoded in different formats, and thus realizes guideline sharing at the execution level.

Decision Making, Computer-Assisted↗

PubMed2002

Representation primitives, process models and patient data in computer-interpretable clinical practice guidelines: a literature review of guideline representation models.

Representation of clinical practice guidelines in a computer-interpretable format is a critical issue for guideline development, implementation, and evaluation. We studied 11 types of guideline representation models that can be used to encode guidelines in computer-interpretable formats. We have consistently found in all reviewed models that primitives for representation of actions and decisions are necessary components of a guideline representation model. Patient states and execution states are important concepts that closely relate to each other. Scheduling constraints on representation primitives can be modeled as sequences, concurrences, alternatives, and loops in a guideline's application process. Nesting of guidelines provides multiple views to a guideline with different granularities. Integration of guidelines with electronic medical records can be facilitated by the introduction of a formal model for patient data. Data collection, decision, patient state, and intervention constitute four basic types of primitives in a guideline's logic flow. Decisions clarify our understanding on a patient's clinical state, while interventions lead to the change from one patient state to another.

Artificial Intelligence↗

PubMed2002

Extended attributes of event monitor systems for criteria-based notification modalities.

The efficacy of event monitors (EMs) at reducing morbidity and mortality of certain clinical conditions (CCs) is well established. In addition, studies have shown that user inverted exclamation mark s preferences on the modality of notification are correlated to the type of reminder or alert. Nonetheless, few institutions have implemented large scale automated monitoring of a considerable number of distinct CCs, and to our knowledge, none of these sizable projects also offer user-customizable communication modalities (CMs) over all monitored conditions. As both the numbers of CMs and CCs increase, the complexity of customizing user preferences amplifies following a geometric progression. This paper demonstrates an automated approach, based on generic notification attributes (NAs) and notification criteria (NC), which significantly simplifies the management and personalization of the CMs for institutions where the manual assignment of a CM for every alert is forbidding. The methods by which these NAs were developed, their significance for existing CCs and their implementation using the Arden Syntax and Guideline interchange format (GLIF) are described. The proposed Criteria-Based Notification is shown to improve two facets of the management of event monitors: 1) the assignment of CMs becomes independent from clinical conditions, de-facto removing institution-specific CMs from the knowledge bases of the event monitors and inserting CC-specific and institution-independent NAs, thus increasing their reusability and sharability; 2) knowledge-based independent NAs facilitate both institution-level management and user-level preference configuration.

Decision Making, Computer-Assisted↗

PubMed2002

GLEE--a model-driven execution system for computer-based implementation of clinical practice guidelines.

We have developed the GLEE system for execution of guidelines encoded in the GLIF3 format. This system can be integrated with a local clinical information system through standard interfaces to EMRs and clinical applications. The execution model of GLEE takes the "system suggests, user controls" approach. A tracing system is used to record the state of guideline steps and their transitions. GLEE provides an internal event-driven execution model that can be hooked up with the clinical event monitor in a local environment. We discuss the execution flexibility provided by GLEE and issues related to its integration in a local environment. Potential use of GLEE includes clinical decision support, quality assurance, guideline development and medical education.

Algorithms↗

PubMedDate not supplied

Challenges and successes of immunization registry reminders at inner-city practices.

OBJECTIVES: To assess the effectiveness of two serial registry reminder protocols and the interactive effects of reminders with child characteristics on immunization rates. METHODS: At an inner city practice network in New York City we randomized 1662 children aged 6 weeks-15 months due or late for a diphtheria-tetanus-pertussis (DTaP) to 3 groups: continuous reminders (as needed), limited reminders (up to 3) and controls, for 6 months. Reminders were triggered by the hospital registry and immunizations were tracked with both the hospital and city registries. Analyses were based on intention to treat. RESULTS: At randomization, the study groups were comparable (9.2 months of age, 77% Latino, 86% Medicaid, 49.3% up-to date). A quarter of the children were sent false reminders, 15% had incorrect contact information, and 15% had missed opportunities for vaccination. In the univariate analysis, reminders improved coverage rates, but only for the children sent continuous reminders (51.2% vs. 44.9% controls, p < .01). Multivariate analysis showed reminders had no independent effect on immunization outcomes. Age, up-to-date and Medicaid status at randomization were strong predictors of a child receiving any subsequent immunization. However, reminders interacted synergistically with Medicaid to increase the likelihood of receiving an immunization. CONCLUSION: At an inner city practice network, registry reminders were not effective at improving immunization outcomes due to major system barriers. Immunization registries are powerful vehicles for identifying children in need of immunizations and generating reminders but system challenges must be addressed if this promise is to be achieved in inner city practices.

Black or African American↗