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 2010
Estimated venous return surface and cardiac output curve precisely predicts new hemodynamics after volume change.
In our extended Guyton's model, the ability of heart to pump blood is characterized by a cardiac output curve and the ability of vasculature to pool blood by a venous return surface. These intersect in a three-dimensional coordinate system at the operating right atrial pressure, left atrial pressure, and cardiac output. ⋯ Using the average values for two logarithmic function parameters, and for two slopes of a surface, we were able to estimate cardiac output curve and venous return surface. The estimated curve and surface predicted new hemodynamics after volume change precisely.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
Mechanical analysis of an oscillatory positive expiratory pressure device used in respiratory rehabilitation.
This article aims to characterize the mechanical behavior of the Acapella Blue, a respiratory rehabilitation device designed to aid sputum clearance. In this scope, the present study initially describes in detail the peak-to-peak oscillation amplitude (App) and peak frequency (fp) behavior, as well as positive pressure level (Ppl), in the flow range more comonly found in practice. The parameters were evaluated in all 5 adjustment levels of the equipment in intervals of 50 mL/s. ⋯ The studied device may produce oscillation in the ranges of ciliary movements and respiratory system resonance frequency of patients with respiratory diseases. Data obtained in this work may help to optimize the use of the Acapella Blue device in respiratory rehabilitation. Suggestions for the practical use of the device are also presented.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
Evaluation of monitoring cardiac output by long time interval analysis of a radial arterial blood pressure waveform using the MIMIC II database.
We recently proposed a technique to estimate relative cardiac output (CO) change by unique long time interval analysis (LTIA) of a radial arterial blood pressure waveform. Here, we evaluated the technique in 169 critically ill patients, while comparing it to previous "pulse contour analysis" techniques, using the public MIMIC II database. ⋯ However, the average absolute thermodilution CO change in each patient was only 12.3%. As the absolute CO change increased, the LTIA technique became increasingly more accurate than the previous techniques.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
Anaesthesia synchronization software: target controlled infusion system evaluation.
Target Controlled Infusion (TCI) systems are based in drug Pharmacokinetic (Pk) and Pharmacodynamic (Pd) models implemented in an algorithm to drive an infusion device. Several studies had compare manual titration of anesthesia and TCI system use; some studies evaluate the performance of the control algorithms for TCI systems, and a considerable number of studies assess the performance of Pk/Pd models implemented into TCI systems. ⋯ The goal of the current study was to assess the performance of the TCI system, Anaesthesia Synchronization Software (ASYS), on clinical set up to evaluate communication consistence (computer - infusion device) and controller performance in real time. These measures provided quantitative and qualitative evidences of software robustness and accuracy to be used at clinical environment.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2010
Statewide validation of a patient admissions prediction tool.
We validate a proprietary system to predict hospital emergency department presentations. A key advantage in planning health service delivery requirements and catering for the large numbers of people presenting to hospitals is the ability to predict their numbers. Year-ahead forecasts of daily hospital presentations were generated for 27 public hospitals in Queensland, Australia from five years of historic data. ⋯ Emergency Department presentations were found to be not random and can be predicted with an accuracy of around 90%. Highest accuracy was over weekends and summer months, and Public Holidays had the greatest variance in forecast accuracy. Forecasts for urban facilities were generally more accurate than regional (accuracy is related to sample size).