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
Removal of ECG artifacts from EEG using a modified independent component analysis approach.
In this paper, we introduce a new automatic method for electrocardiogram (ECG) artifact elimination from the electroencephalogram (EEG) or the electrooculogram (EOG). It is based on a modification of the independent component analysis (ICA) algorithm which gives promising results while only using a single-channel EEG (or EOG) and the ECG. ⋯ Two hundred successive interference peaks were examined in each excerpt to compute correction rates. We found that our modified ICA was the most robust to various waveforms of cardiac interference and to the presence of others artifacts, with a correction rate of 91.0%, against 83.5% for EAS and 83.1% for AF.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Predicting ICU hemodynamic instability using continuous multiparameter trends.
Identifying hemodynamically unstable patients in a timely fashion in intensive care units (ICUs) is crucial because it can lead to earlier interventions and thus to potentially better patient outcomes. Current alert algorithms are typically limited to detecting dangerous conditions only after they have occurred and suffer from high false alert rates. Our objective was to predict hemodynamic instability at least two hours before a major clinical intervention (e.g., vasopressor administration), while maintaining a low false alert rate. ⋯ Area under receiver-operating curve (ROC) 0.83+/-0.03, sensitivity 0.75+/-0.06, and specificity 0.80+/-0.07; if the specificity is targeted at 0.90, then the sensitivity is 0.57+/-0.07. Based on our preliminary results, we conclude that the algorithms we developed using HR and BP trend data may provide a promising perspective toward reliable predictive alerts for hemodynamically unstable patients.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Asymmetry in lung sound intensities detected by respiratory acoustic thoracic imaging (RATHI) and clinical pulmonary auscultation.
RATHI was introduced as an attempt to further improve the association between anatomical zones and specific breathing activity, both spatially and temporally. This work compares RATHI with clinical pulmonary auscultation (PA) to assess the concordance between both procedures to detect asymmetries in lung sound (LS) intensities. Twelve healthy young males participated in the study and were auscultated by two experts. ⋯ By RATHI, most of the subjects showed asymmetries between apical and basal regions higher than 20%, whereas between left and right hemithorax asymmetries higher than 20% occurred only half of the time. RATHI and PA agreed 83 to 100% when apical to base acoustical information was compared, but when left to right asymmetries were considered these figures were about 40 to 50%. We concluded that RATHI has advantages as it gave more detailed and measurable information on LS than clinicians, who could not detect intensity asymmetries mainly below 20%.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Preliminary study on physiological changes of hemorrhagic shock in rats.
Hemorrhagic shock is a common cause of death in emergency rooms. The objective evaluation of hemorrhagic shock is very important for early diagnosis and treatment. ⋯ We constructed an integrated system to be able to control bleeding and to simultaneously measure bio-signals such as ECG, blood pressure, temperature, and respiration. In order to verify the system, we measured the bio-signals mentioned above while hemorrhagic shock was induced by withdrawing blood (2.5 ml / 100 g / 15 min) from a femoral vein for 10 rats.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2008
Investigation of photoplethysmogram morphology for the detection of hypovolemic states.
Medics and first responders to emergencies are often faced with monitoring and assessing victims with very limited resources. Therefore, there is an inherent need for a real-time ambulatory monitoring capability that is portable and low power. This is particularly important for physiological monitoring of life-threatening conditions such as internal hemorrhaging. ⋯ In this paper, we compared the PPG morphology with pulse transit time (PTT), which has been investigated for clinical and ambulatory applications. The indicators were tested on data obtained from experiments using lower body negative pressure (LBNP) as a model to simulate hemorrhage in humans. The results of this study indicate that PPG morphology is associated with pulse pressure (systolic minus diastolic blood pressure) and is therefore a promising feature for detection and real-time tracking of hypovolemic states.