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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This paper describes an accurate, economical, and portable device that helps to locate the position of an endotracheal tube (ETT) in situ. The device uses an array of magnetic field sensors to detect an anomaly in magnetic field caused by magnet embedded near the cuff of an ETT, and displays an intuitive map of relative magnetic field intensity under the sensor area. The device provides real-time feedback of the position to a clinician, so that corrective measures can be taken if the ETT is determined to be outside of normal positioning with respect to the patient's airway. Variations of the proposed design are suitable for continuous monitoring.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Comparative StudyEvaluation tests for eye tracking systems.
In this paper, we describe the tests developed by our research team to evaluate the performance of eye tracking algorithms to quantify vertical and horizontal eye movements. To perform the tests, we created a special library to generate synthetic eye images, where we can control most characteristics of the eyes. It is possible to simulate the different situations observed during the acquisition of eye images of a real subject.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Exploiting the existence of temporal heart-rate patterns for the detection of trauma-induced hemorrhage.
Unattended hemorrhage is a major source of mortality in trauma casualties. In this study, we explore a set of prehospital heart rate (HR) time-series data collected from 358 civilian casualties to examine whether temporal HR patterns can be used for automated hemorrhage identification. Continuous and reliable HR time series are fragmented into overlapping segments of 128 s, with a 118-s overlap between each two neighboring segments, which are projected into a wavelet coefficient space using the Haar wavelet function. ⋯ The clustering algorithm identifies 162 HR patterns. The most frequent pattern is observed in 11 (23%) hemorrhage and 16 (5%) control patients, which is a significant association (p<0.05, chi-square test). When the top 10 patterns are combined for hemorrhage detection, their sensitivity and specificity are 0.68 and 0.79, respectively, and when the top 20 patterns are used sensitivity increases to 0.77 and specificity decreases to 0.71.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Automation in anesthesia: computer controlled propofol infusion and data acquisition.
This work presents the improvement of a software for a clinical setup, the Anesthesia Synchronization Software (ASYS). The first version presented the data acquisition from cerebral monitors and a partial control with Target Controlled Infusion (TCI) system. Based on pharmacokinetic models, the effect-site and plasma concentrations can be related with the drug dose infused and vice versa. This later version comes with the implementation of the hemodynamic monitor always present in operating rooms and with the full TCI system developed to determine the infusion rates of the drug which are given as commands to the infusion pumps.
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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.