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 2006
Circuit compliance compensation in lung protective ventilation.
Lung protective ventilation utilizes low tidal volumes to ventilate patients with severe lung pathologies. The compensation of breathing circuit effects, i.e. those induced by compressible volume of the circuit, results particularly critical in the calculation of the actual tidal volume delivered to patient's respiratory system which in turns is responsible of the level of permissive hypercapnia. ⋯ Experimental tests conducted in-vitro show that the actual tidal volume can be reliably estimated if the compliance of the breathing circuit is measured with the same parameters and ventilation technique that will be utilized in lung protective ventilation. Differences between volume and pressure controlled ventilation are also quantitatively assessed showing that pressure controlled ventilation allows a more reliable compensation of breathing circuit compressible volume.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Heat transfer model of hyporthermic intracarotid infusion of cold saline for stroke therapy.
A 3-dimensional hemispheric computational brain model is developed to simulate infusion of cold saline in the carotid arteries in terms of brain cooling for stroke therapy. The model is based on the Pennes bioheat equation, with four tissue layers: white matter, gray matter, skull, and scalp. ⋯ The finite difference method was employed to solve the system of partial differential equations. This model demonstrated a reduction in brain temperature, at the stroke lesion, to 32 degrees C in less than 10 minutes.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Observer design in switching control of neuromuscular blockade: clinical cases.
This paper concerns the application of multiple model switched methods to the control of neuromuscular blockade of patients undergoing anaesthesia. Since the model representing the neuromuscular blockade process is subject to a high level of uncertainty due both to inter-patient variability and time variations, switched methods provide the adaptation capability needed to achieve the desired performance. ⋯ Guidelines are provided for adequate selection of the characteristic polynomial defining the observer error dynamics. Second, clinical results using atracurium as blocking agent are reported in order to illustrate the use of the proposed control structure in actual clinical practice.
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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 2005
Capacity of brain cooling via ventilating oxygen at low temperature over respiratory tract.
Cerebral hypothermia is a rather useful way to improve outcome after brain injury. In this paper, the capacity of cooling oxygen ventilation (COV) during cerebral circulation arrest was theoretically evaluated. ⋯ However, its capacity on lowering the deep brain temperature is very limited. Therefore more powerful cooling strategies should be investigated to realize an efficient cooling on the target cerebral tissue.