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
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.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2011
Training to improve volitional muscle activity in clinically paralyzed muscles for neuroprosthesis control.
Neuroprostheses are devices that use electrical stimulation to activate paralyzed muscles in a coordinated manner to restore functional movements. These systems utilize a voluntarily-generated command signal for control of function. Current command signals include electromyographic (EMG) activity from muscles above the injury level that remain under volitional control. ⋯ Our recent research suggests that volitional muscle activity from below the injury level in individuals with motor complete spinal cord injury may be a viable source of command information. The signals from these muscles are small, and therefore the goal of this study is to determine if training using visual feedback can improve the quality of these muscle signals. Results to date indicate that training with visual feedback can increase both the magnitude and consistency of EMG signals in clinically paralyzed muscles.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2011
Wavelet-based features for characterizing ventricular arrhythmias in optimizing treatment options.
Ventricular arrhythmias arise from abnormal electrical activity of the lower chambers (ventricles) of the heart. Ventricular tachycardia (VT) and ventricular fibrillation (VF) are the two major subclasses of ventricular arrhythmias. While VT has treatment options that can be performed in catheterization labs, VF is a lethal cardiac arrhythmia, often when detected the patient receives an implantable defibrillator which restores the normal heart rhythm by the application of electric shocks whenever VF is detected. ⋯ This might eventually lead to an objective way of analyzing arrhythmias in the overlap zone and computing their degree of affinity towards VT or VF. A database of 24 human ventricular arrhythmia tracings obtained from the MIT-BIH arrhythmia database was analyzed and wavelet-based features that demonstrated discrimination between the VT, VF, and VT-VF groups were extracted. An overall accuracy of 75% in classifying the ventricular arrhythmias into 3 groups was achieved.