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
A simple and efficient algorithm with a coarse to fine approach for arterial beat pulse detection.
This paper presents a simple algorithm for arterial beat pulse detection. It consists in a coarse to fine approach : the first step is performed with a lifting Haar wavelet transform with thresholding and provides search intervals, the second step is to localize the beat pulse in the original signal within these areas. Thanks to online available database, the performance of this algorithm can be compared to others and its ability to detect peaks is sufficient considering its low amount of calculation.
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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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In this paper, we present a subspace approach for functional magnetic resonance imaging (fMRI) time series analysis. The signal subspace is formed of the eigenvectors of data correlation matrix. The approach is utilized both for single-trial estimation of blood oxygenation level dependent (BOLD) responses in fMRI time series and for studying the functional connectivity of BOLD responses from different spatial areas.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
Effect of the needle tip height on the puncture force in a simplified epidural anesthesia simulator.
The purpose of the research is to create a safer needle used for epidural anesthesia. Medical doctors identify the location of the epidural space by feeling the drop of force in advancing the needle tip. A greater drop of force makes for a safer needle. ⋯ We found no obvious tendency regarding the effect of the insertion speed. The drop in the force in the rubber was one-fourth greater than that in the bone. Our conclusions are that 1) the higher the needle tip design, the greater the drop in force can be achieved; and that 2) silicone rubber with a hardness of 50 Hs is similar to the ligamentum flavum.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2007
The complete electrode model for imaging and electrode contact compensation in electrical impedance tomography.
Electrical Impedance Tomography (EIT) is an imaging modality which currently shows promise for the detection and characterization of breast cancer. A very significant problem in EIT imaging is the proper modeling of the interface between the body and the electrodes. We have found empirically that it is very difficult, in a clinical setting, to assure that all electrodes make satisfactory contact with the body. ⋯ To compensate for these problems, we have developed a hybrid nonlinear-linear reconstruction algorithm in which we first estimate electrode surface impedances, using a Newton-type iterative optimization procedure with an analytically computed Jacobian matrix. We subsequently make use of a linearized algorithm to perform a three-dimensional reconstruction of perturbations in both contact impedances and in the spatial distributions of conductivity and permittivity. Results show that, using this procedure, artifacts due to electrodes making poor contact can be greatly reduced.