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
Continuous cardiac output and left atrial pressure monitoring by pulmonary artery pressure waveform analysis.
We introduce a novel technique for continuous (i.e., automatic) monitoring of cardiac output (CO) and left atrial pressure (LAP) by mathematical analysis of a pulmonary artery pressure (PAP) waveform. To obtain an initial evaluation of the technique, we applied it to PAP waveforms obtained from nine critically ill patients and compared the resulting CO and LAP estimates with standard operator-dependent thermodilution and pulmonary capillary wedge pressure measurements, respectively. We report that the technique achieved an overall CO error of 17.2% and an overall LAP error of 15.8%. With further testing, the technique may ultimately be employed so as to permit, for the first time, continuous CO and LAP monitoring in critically ill patients.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Evaluation of external cardiac massage performance during hypogravity simulation.
Preservation of astronaut crew health during an exploration mission to the Moon or Mars will be crucial to mission success. The likelyhood of a life threatening medical condition occurring during a mission to Mars has been estimated by NASA to be 1% per year. Since basic life support is a vital skill in critical care medicine, plans must be in place for cardiopulmonary resuscitation in both microgravity and hypogravity (i.e. on the surface of the Moon or Mars). ⋯ Elbow flexion was measured using an electrogoniometer in order to assess the use of arm muscles to achieve chest compressions. This study found that depth (Lunar and Mars) and rate (Mars) of chest compression was below American Heart Association recommendations during hypogravity simulation in the female group. Furthermore, elbow flexion proved to be significantly greater during Lunar and Mars hypogravity simulation than that of the 1G control condition, suggesting that upper arm force may be used to counter the loss of body weight in an attempt to maintain adequate chest compression under these conditions.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Blind identification of the central aortic pressure waveform from multiple peripheral arterial pressure waveforms.
We introduce a blind identification technique to reconstruct the clinically more relevant central aortic pressure waveform from multiple less invasively measured peripheral arterial pressure waveforms. We conducted initial testing of the technique in two swine in which peripheral arterial pressure waveforms from the femoral and radial arteries and reference central aortic pressure were simultaneously measured during diverse hemodynamic conditions. We report an overall error between the estimated and measured central aortic pressure waveforms of 4.8%. Potential clinical applications of the technique may include critical care monitoring with respect to invasive catheter systems and emergency and home monitoring with respect to non-invasive arterial pressure transducers.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
ReviewIntelligent alarm processing into clinical knowledge.
Alarmed physiological monitors have become a standard part of the ICU. While the alarms generated by these monitors can be important indicators of an altered physiological condition, most are unhelpful to medical staff due to a high incidence of false and clinically insignificant alarms. ⋯ In this paper we review the current state of intelligent alarm processing and describe an integrated systems methodology to extract clinically relevant information from physiological data. Such a method would aid significantly in the reduction of false alarms and provide nursing staff with a more reliable indicator of patient condition.
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Conf Proc IEEE Eng Med Biol Soc · Jan 2006
Controlled Clinical TrialInformation flow to assess cardiorespiratory interactions in patients on weaning trials.
Nonlinear processes of the autonomic nervous system (ANS) can produce breath-to-breath variability in the pattern of breathing. In order to provide assess to these nonlinear processes, nonlinear statistical dependencies between heart rate variability and respiratory pattern variability are analyzed. ⋯ The results show lower complexity with an increase of information flow in group A than in group B. Furthermore, a more (weakly) coupled nonlinear oscillator behavior is observed in the series of group A than in B.