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
Algorithm for automatic beat detection of cardiovascular pressure signals.
Pressure beat detection is an integral part of most analysis techniques for arterial blood pressure (ABP), intracranial pressure (ICP), and pulse oximetry (SpO(2)) signals. Beat detection has been used to estimate heart rate in the ABP signal, to classify ICP morphologies, and to estimate blood pressure using pulse oximeter waveforms. This paper describes an algorithm that was developed to detect pressure peak beats in ABP, ICP, and SpO(2) signals. When compared to the expert annotation of several signals consisting of over 42,500 pressure beats, the algorithm detected pressure peaks with an average sensitivity of 99.6% +/- 0.27 and an average positive predictivity of 98.6% +/- 1.1.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Clinical TrialValidation of the Index of Consciousness (IoC) during sedation/analgesia for ultrasonographic endoscopy.
The level of consciousness of patients undergoing surgery evolves continuously as the effect of the anesthetic agents is counteracted by the surgical stimuli. The monitors of depth of anesthesia, based on the analysis of the electroencephalogram (EEG), have been progressively introduced into the daily practice to provide additional information about the state of the patient. ⋯ A good correlation is found between both indexes. Furthermore, IoC presents a significantly higher prediction probability Pk of the level of sedation than BIS, and can thus be considered as an interesting measure of the level of consciousness.
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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.