RESUMO
We present a language for representing context-sensitive temporal probabilistic knowledge. Context constraints allow inference to be focused on only the relevant portions of the probabilistic knowledge. We provide a declarative semantics for our language. We present a sound and complete algorithm for computing posterior probabilities of temporal queries, as well as an efficient implementation of the algorithm. Throughout we illustrate the approach with the problem of reasoning about the effects of medications and interventions on the state of a patient in cardiac arrest. We empirically evaluate the efficiency of our system by comparing its inference times on problems in this domain with those of standard Bayesian network representations of the problems.
Assuntos
Inteligência Artificial , Simulação por Computador , Sistemas Inteligentes , Modelos Estatísticos , Tempo , Algoritmos , Teorema de Bayes , Parada Cardíaca/terapia , Humanos , Lógica , Monitorização Fisiológica/instrumentação , Prognóstico , Software , Terapia Assistida por Computador/instrumentaçãoRESUMO
We present a language for representing context-sensitive temporal probabilistic knowledge. Context constraints allow inference to be focused on only the relevant portions of the probabilistic knowledge. We provide a declarative semantics for our language and an implemented algorithm (BNG) that generates Bayesian networks to compute the posterior probabilities of queries. We illustrate the use of the BNG system by applying it to the problem of modeling the effects of medications and other interventions on the condition of a patient in cardiac arrest.
Assuntos
Simulação por Computador , Parada Cardíaca/terapia , Modelos Cardiovasculares , Redes Neurais de Computação , Inteligência Artificial , Teorema de Bayes , Parada Cardíaca/fisiopatologia , Humanos , ProbabilidadeRESUMO
Recent technology has produced high-flow and large-lumen catheters as well as other angiographic accessories to enhance the visualization of the coronary arteries during diagnostic and percutaneous transluminal coronary angioplasty (PTCA) procedures. In spite of these technological advances, there are still many cases in which the quality of the coronary angiography could be significantly improved. This paper reports on a clinical evaluation of a hand-held power syringe. The syringe offers the ability to power inject contrast safely and effectively during routine angiograms as well as through guiding catheters with the balloon catheter present during PTCA. At the same time, control of the injection is equal to that associated with manual syringes.
Assuntos
Angiografia/instrumentação , Cateterismo/instrumentação , Radiografia Intervencionista/instrumentação , Seringas , Angioplastia Coronária com Balão/instrumentação , Dióxido de Carbono , Cateterismo Cardíaco , Meios de Contraste/administração & dosagem , Angiografia Coronária , Diatrizoato/administração & dosagem , Diatrizoato de Meglumina/administração & dosagem , Combinação de Medicamentos/administração & dosagem , Fontes de Energia Elétrica , Desenho de Equipamento , Humanos , ReologiaRESUMO
The effect of the use of small-volume medication nebulizers on oropharyngeal colonization with potentially pathogenic Gram-negative bacilli was investigated in 95 patients with respiratory disease, of whom 54 used nebulizers and 41 were controls. Inhalation therapy had a significant effect on colonization, with a relative risk of more than four. Age over 60 years also showed a significant association with colonization. One-third of the nebulizers sampled were contaminated, 71% with Gram-negative bacilli. A direct route of contamination could be demonstrated in 28% of the patients. Medication nebulizers should be thoroughly cleaned after use and stored dry between patients.
