Journal of clinical monitoring and computing
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J Clin Monit Comput · Jan 2000
Hierarchical rule-based monitoring and fuzzy logic control for neuromuscular block.
The important task for anaesthetists is to provide an adequate degree of neuromuscular block during surgical operations, so that it should not be difficult to antagonize at the end of surgery. Therefore, this study examined the application of a simple technique (i.e., fuzzy logic) to an almost ideal muscle relaxant (i.e., rocuronium) at general anaesthesia in order to control the system more easily, efficiently, intelligently and safely during an operation. ⋯ The results showed that a hierarchical rule-based monitoring and fuzzy logic control architecture can provide stable control of neuromuscular block despite the considerable individual variation in neuromuscular block required among patients. Also, there was less variation in T1% error compared with that of previous study on mivacurium. Meanwhile, the consistent medium CV of the MIR of both rocuronium and mivacurium indicated a good controller activity which is able to withstand noise, diathermy effect, artifacts and surgical disturbances.
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J Clin Monit Comput · Jan 2000
Partial CO2 rebreathing indirect Fick technique for non-invasive measurement of cardiac output.
Evaluation in animals of a non-invasive and continuous cardiac output monitoring system based on partial carbon-dioxide (CO2) rebreathing indirect Fick technique. ⋯ The partial CO2 rebreathing technique for measurement of cardiac output is non-invasive, automated, and based on the well accepted Fick principle. The limits of agreement between NICO and TDco is within the recommended value for NICO to be a clinically acceptable method for cardiac output measurement. The results of this canine study show that NICO performed as well, and in some cases better, than other currently available non-invasive cardiac output techniques over a wide range of cardiac outputs.
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J Clin Monit Comput · Jan 2000
Bispectral index (BIS) and burst suppression: revealing a part of the BIS algorithm.
The bispectral index (BIS) is a complex EEG parameter which integrates several disparate descriptors of the EEG into a single variable. One of the subparameters incorporated in the BIS is the suppression ratio, quantifying the percentage of suppression during burst suppression pattern. The exact algorithm used to synthetize the information to the BIS value is unpublished and still unknown. This study provides insight into the integration of the suppression ratio into the BIS algorithm. ⋯ Suppression ratio values > 40% are linearly correlated with BIS values from 30 to 0. An increasing anesthetic drug effect resulting in an increase of the duration of suppression to a suppression ratio up to 40% is not adequately reflected by the BIS value.
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J Clin Monit Comput · Jan 2000
ReviewNon-invasive imaging of regional lung function using x-ray computed tomography.
The use of imaging technologies has progressed beyond the depiction of anatomic abnormalities to providing non-invasive regional structure and functional information in intact subjects. These data are particularly valuable in studies of the lung, since lung disease is heterogeneous and significant loss of function may occur before it is detectable by traditional whole lung measurements such as oxygenation, compliance, or spirometry. ⋯ In addition, using the radiodense gas xenon (Xe) as a contrast agent, regional ventilation or gas transport may also be obtained. This communication will review recent advances in CT based techniques for the measurement of regional lung function.
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J Clin Monit Comput · Jan 2000
Comparative Study Clinical TrialNon-invasive estimation of cardiac output in critical care patients.
This study was carried out to compare cardiac output measurements determined by thermodilution and by Portapres, a non-invasive system. ⋯ To date, Portapres measurements cannot replace thermodilution cardiac output estimations. Fluctuations of finger arterial perfusion due to hemodynamic instability, hypothermia and catecholamines may be responsible for problems of Portapres use in critically ill patients.