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 2011
EMG contributes to improve Cerebral State Index modeling in dogs anesthesia.
Cerebral State Index (CSI) is a measure of depth of anesthesia (DoA) developed for humans, which is traditionally modeled with the Hill equation and the propofol effect-site concentration (Ce). The CSI has been studied in dogs and showed several limitations related to the interpretation of EEG data. Nevertheless, the CSI has a lot of potential for DoA monitoring in dogs, it just needs to be adjusted for this species. ⋯ In fact, the EMG introduction in CSI model significantly decreased the modeling error: 11.8 [8.6; 15.2] (fuzzy logic) versus 20.9 [16.4; 29.0] (Hill). This work shows that CSI modeling in dogs can be improved using the current human anesthesia set-up, once the EMG signal is acquired simultaneously with the CSI index. However, it does not invalidate the search of new DoA indices more adjusted to use in dog's anesthesia.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2011
Sequential versus concurrent computation of complex model systems for medical decision support.
Medical Decision Support Systems employ mathematical models to optimize therapy settings. The mathematical models are used to predict patient reactions towards alteration in the therapy regime. This prediction should not be limited to one detail but should feature a broad picture. ⋯ Evaluation of the new approach showed that results feature a discrepancy lower than 2.5% compared to the results computed by the concurrent approach. Simulation error could be decreased to 2% by improving the precalculation of the interface signals. Computing costs have been decreased by a factor of 17.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2011
NIRS study of cerebral oxygenation and hemodynamics in neonate at birth.
To study the changes of cerebral oxygenation and hemodynamics in normal neonates at 2-5 min post-birth and understand the effects of pregnancy-induced hypertension (PIH) upon cerebral oxygenation and hemodynamics in newborn neonates. The near infrared spectroscopy (NIRS) was employed to measure the absolute quantity of brain tissue oxygen saturation (rSO2) in newborn neonates and the changes of concentrations of deoxyhemoglobin (Hb) and oxygenation hemoglobin (HbO2) with time relative to initial values to further obtain the changes of total hemoglobin (tHb) and cerebral perfusion (denoted by HbD). ⋯ In neonates born of PIH mothers at 3-5 min post-birth, the changes of tHb were markedly higher than those in the normal infants, p<0.05; at 2-5 min post-birth, the changes were markedly lower than the normal term infants. We concluded that NIRS can detect the changes of cerebral oxygenation and blood flow in a non-invasive and effective way.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2011
Respiratory rate estimation using respiratory sinus arrhythmia from photoplethysmography.
Respiratory rate (RR) is an important measurement for ambulatory care and there is high interest in its detection using unobtrusive mobile devices. For this study, we investigated the estimation of RR from a photoplethysmography (PPG) signal that originated from a pulse oximeter sensor and had a sub-optimal sampling rate. We explored the possibility of estimating RR by extracting respiratory sinus arrhythmia (RSA) from the PPG-derived heart rate variability (HRV) measurement using real-time algorithms. ⋯ Both PPG and ECG RR estimation techniques were more powerful and reliable in cases of spontaneous ventilation than when pressure controlled ventilation was used. The analysis of cases containing artifacts in the PPG revealed a significant increase in RR error, a trend that was less pronounced for controlled ventilation. These results indicate that the estimation of RR from the sub-optimally sampled PPG signal is possible and more reliable than from the ECG.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2011
Robust video-oculography for non-invasive autonomic nerve quantification.
A relationship between autonomic nerves activity and depression or Alzheimer's disease has been reported. The quantification of autonomic nerves is expected to serve as a tool for quantifying the of severity of the disease or for early detection. Video-oculography is known as a non-invasive and reliable procedure of measurement of pupil response and is used in clinical practice. ⋯ In this study, we developed a robust and accurate method to measure the transition of pupil size. The proposed method introduces an interpolation process using an active contour model and ellipse estimation with selection of reliable contour points and attains robust measurement of pupil area against the abovementioned difficulties. We confirmed our method achieved an extraction accuracy of 98.3 % in precision and 98.9% in recall in average on the tested a total of 8,518 image frames from 30 movies.