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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We describe a novel algorithm to estimate the pulse pressure variation index (PPV) from arterial blood pressure signals (ABP). PPV has been shown to be one of the best predictors of fluid responsiveness in mechanically ventilated subjects. Our PPV algorithm uses a non-linear technique for envelope estimation, eliminating the need for automatic beat detection. ⋯ The algorithm was validated against the continuous PPV output obtained from the commercially available PiCCOreg system and gold standard expert PPV manual annotations. The data consists of ABP taken from subjects who experienced rapid changes in hemodynamics. This data comprised over six hours of continuous ABP monitoring.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Quantitative EEG assessment of brain injury and hypothermic neuroprotection after cardiac arrest.
In this paper we provide a quantitative electroencephalogram (EEG) analysis to study the effect of hypothermia on the neurological recovery of brain after cardiac arrest. We hypothesize that the brain injury results in a reduction in information of the brain rhythm. To measure the information content of the EEG a new measure called information quantity (IQ), which is the Shannon entropy of decorrelated EEG signals, is developed. ⋯ In addition, EEG signal recovery under normothermic (37 degrees C) and hypothermic (33 degrees C) resuscitation following 5, 7 and 9 minutes of cardiac arrest is recorded and analyzed. Experimental results show that the IQ is higher for hypothermic than normothermic rats. The results quantitatively support the hypothesis that hypothermia accelerates the recovery of brain injury after cardiac arrest.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Using a generalized neural network to identify airway obstructions in anesthetized patients postoperatively based on photoplethysmography.
Photoplethysmography has been recently studied asa non-invasive indicator of circulatory and respiratory function. In this study, photoplethysmographic (PPG) data were recorded from patients under the influence of anesthesia, but not intubated. ⋯ This classifier considers inter-subject variability so that it generalizes well to a large population. This classifier provided 86.1%accuracy to classify segments as being times of 'obstructed' vs.'normal' airways status.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
ReviewIntegrating data, models, and reasoning in critical care.
Modern intensive care units (ICUs) employ an impressive array of technologically sophisticated instrumentation to provide detailed measurements of the pathophysiological state of each patient. Providing life support in the ICU is becoming an increasingly complex task, however, because of the growing volume of relevant data from clinical observations, bedside monitors, mechanical ventilators, and a wide variety of laboratory tests and imaging studies. ⋯ There is a critical need to integrate the disparate clinical information into a single, rational framework and to provide the clinician with hypothesis-driven displays that succinctly summarize a patient's trajectory over time. In this paper, we present our recent efforts towards the development of such an advanced patient monitoring system that aims to improve the efficiency, accuracy, and timeliness of clinical decision making in intensive care.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2005
The Establishment of the Mathematical Model of the 2ndDegree Burn Injury of Human Tissues and Its Application.
A quantitative analysis of the 2nddegree burn injury of human tissues and the relevant mathematical model are presented in this paper. Unlike the general criterion extensively adopted by doctors that pay much attention to the degrees of the skin burn damage such as the area, depth and color of the damaged skins, the paper emphasizes the cause-and-effect of the 2nddegree burn injury of the human tissues. ⋯ The comparisons of the theoretical study with the experimental data have been made and the results are quite satisfactory. The application of the mathematical model in the test of thermal protective performance of fire protection clothing is also presented.