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
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
Additive and multiplicative noise reduction by back propagation neural network.
A novel filter is proposed by applying back propagation neural network (BPNN) ensemble where the noisy signal and the reference one are the same. The neural network(NN) ensemble filter not only well reduces additive and multiplicative white noise inside signals, but also preserves signals' characteristics. ⋯ Furthermore, it is presented of the relationship between noise reduction and bandwidth of noises. The performance of the NN ensemble filter is demonstrated in computer simulations and actual electroencephalogram (EEG) signals processing.
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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
Fluid resuscitation: computer simulation and animal experiments.
The purpose of this study was to investigate the hemodynamic system in hemorrhagic shock and to estimate the effects of different infusion fluids and rates on the recovery of the bleeding patient. A mathematical model of the hemodynamic system was developed including fluid transfer to and from the interstitium for different types of fluids. ⋯ The computer simulation followed successfully experimental data collected in five different experiments. Thus, it may now serve as an advanced tool for evaluating and analyzing effects of different fluids and optimize fluid regimen.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
Modeling state entropy of the EEG and auditory evoked potentials: hypnotic and analgesic interactions.
Because of the complexity of raw electroencephalogram (EEG), for the anesthesiologist it is very difficult to evaluate the patient's hypnosis state. Because of this, several depth of anesthesia monitors have been developed, and are in current use at the operating room (OR). These monitors convert the information supplied by the EEG or derived signals into a simple, easy to understand index. ⋯ Hypnotic and analgesic drugs interact in different ways throughout the anaesthesia stages. The models obtained captured the different dynamic interaction of drugs, during the induction and maintenance phases, demonstrating that the model must have incorporated all this information in order to perform satisfactorily. Other information like haemodynamic variables might be included in the search for the optimum model.