Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
Comparative Study Clinical TrialClassifying depth of anesthesia using EEG features, a comparison.
Various EEG features have been used in depth of anesthesia (DOA) studies. The objective of this study was to find the excellent features or combination of them than can discriminate between different anesthesia states. Conducting a clinical study on 22 patients we could define 4 distinct anesthetic states: awake, moderate, general anesthesia, and isoelectric. ⋯ The maximum accuracy (99.02%) achieved using approximate entropy as the feature. Some other features could well discriminate a particular state of anesthesia. We could completely classify the patterns by means of 3 features and Bayesian classifier.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
Comparative StudyA comparative evaluation between conditions of the wrist band capacitively-coupled ECG recording through signal-to-noise ratio.
The purpose of this study is to evaluate the performance to measure ECG recording based on signal-to-noise ratio of ECG signals recorded with three types of electrodes in four experimental conditions for discussion on appropriate form of the electrodes. The wrist band shaped capacitively-coupled electrodes have been developed. We evaluated the signal-to-noise ratios with statistical methods when the reference and the properties of the electrodes were substituted. From our results, it is indicated that not only performance of the electrodes themselves but also stabilization of electrodes around skin are important for steady ECG recording.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
The role of intracarotid cold saline infusion on a theoretical brain model incorporating the circle of willis and cerebral venous return.
This study describes a theoretical model of brain cooling by intracarotid cold saline infusion which takes into account redistribution of cold perfusate through the circle of Willis (CoW) and cold venous return (VR) from the head. This model is developed in spherical coordinates on a four tissue layer hemispherical geometrical configuration. Temperature evolution is modeled according to the Pennes bioheat transfer equation. ⋯ The temperature effect in the CoW model was present but less robust in the ipsilateral anterior region, as final temperature was 32 degrees C. However, cooling was also achieved in contralateral and posterior brain regions. This model continues to demonstrate the feasibility of intracarotid cold saline infusion for ischemic stroke therapy.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
Clinical TrialModeling anesthetic drugs' pharmacodynamic interaction on the bispectral index of the EEG: the influence of heart rate.
The effect of drugs' interaction on the brain signal Bispectral Index (BIS) is of great importance for an anesthesia control drug infusion system. In this study, the objective was to inspect the influence of patient's heart rate on the effect of the drugs on BIS. With this goal, the patient's heart rate was incorporated in an drug interaction model. ⋯ The results showed that the model with time changing parameters incorporating patient's heart rate has a better performance than a non adjusted model. Three clusters of models were also identified using the fuzzy c-means algorithm. These clusters will help to distinguish between different patients' dynamics.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
Diagnosis of hemorrhage in a prehospital trauma population using linear and nonlinear multiparameter analysis of vital signs.
In this study, we analyzed a dataset of time-series vital-signs data collected by standard Propaq travel monitor during helicopter transport of 898 civilian trauma casualties from the scene of injury to a receiving trauma center. The goals of the analysis are two fold. First, to determine which combination of the automatically-collected and -qualified vital signs provides the best discrimination between casualties with and without major hemorrhage. ⋯ We randomly selected a subset of the casualties to train and test the classifiers with multiple combinations of the vital-signs variables, and used the area under the receiver operating characteristic curve (ROC AUC) as a decision metric. Based on the results of 100 simulations, we observe that: (i) the best two features obtained are systolic blood pressure and heart rate (mean AUC = 0.75 from a linear classifier), and (ii) the use of nonlinear classifiers does not improve discrimination. These results support earlier findings that the interaction of systolic blood pressure and heart rate is useful for the identification of trauma hemorrhage and that linear classifiers are adequate for many real-world applications.