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 2008
Fetal distress diagnosis using heart rate variability analysis: design of a high frequency variability index.
Routine monitoring of Fetal Heart Rate (FHR) during labor enables diagnosis of fetal distress and appropriate management by the medical staff. Diagnosis of fetal distress relies mainly on a subjective visual assessment of FHR variations using baseline level, oscillations magnitude, decelerations and their time-relation to the parturient uterine contractions. Strong intra and inter-observer discrepancies exist with this widely used technique, and sometimes requires fetal scalp blood sample pH measurement, which is not fully reliable either. ⋯ We tested this new index on 21 fetuses where FHR was recorded during labor for an observational clinical trial. FHR recordings were separated in two groups given the fetal arterial pH obtained after birth: group 1 - no distress, pH >= 7.15, N=16 and group 2 - fetal distress, pH 7.15, N=5. The new index was significantly higher in group 1 than in group 2 (non parametric Mann Whitney U-test, p=0.01).
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Phase space reconstruction approach for ventricular arrhythmias characterization.
Ventricular arrhythmias, especially tachycardia and fibrillation are one of the main causes of sudden cardiac death. Therefore, the development of methodologies, enable to detect their occurrence and to characterize their time evolution, is of fundamental importance. ⋯ Features from current and previous time windows are provided to a dynamic neural network classifier, enabling arrhythmias detection and evolution trends assessment. Sensitivity and specificity values, evaluated from public MIT-BIH databases, show the effectiveness of the proposed strategy.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Model predictive control of depth of anaesthesia: guidelines for controller configuration.
The paper presents a feasibility study on the use of Model based Predictive control (MPC) to regulate the level of Depth of Anaesthesia (DoA) when measured by the BIS index. Pharmacokinetic/pharmacodynamic nonlinear models of DoA when Propofol and Remifentanil are used as hypnotic and analgesic drugs are linearized around the desired working point for DoA in order to obtain a linear state-space model coupled with an extra integrator to include integral action in the control. This state-space model is then used in a MPC algorithm. The main contribution of the paper consists in the characterization of the influence of the different design parameters in the MPC performance when controlling DoA.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Interpolation of the subjective score of visually-induced motion sickness by using physiological parameters.
In order to investigate the effect of visually-induced motion sickness in actual video images, this study proposes a method of interpolation for the subjective score, which has low time and quantitative resolutions, by using physiological parameters. The model which represents the change in subjective score of VIMS was expressed as multiple regression equations in which input parameters are cardiovascular indices such as heart rate variability. The estimation results indicated that the model can represent, in higher resolution, the change in the subjective score of the subjects who have induced nausea.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Clinical TrialA neuro-fuzzy approach for predicting hemodynamic responses during anesthesia.
The effect of drugs' interaction on the hemo-dynamic variables is of great importance when considering patient's safety and stability. It is also important for control infusion systems during anesthesia. ⋯ The use of subtractive clustering improved the model performance on the testing data set. The fuzzy model is able to capture the synergistic interaction between the two drugs, but other influences were detected.