Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2006
The use of joint time frequency analysis to quantify the effect of ventilation on the pulse oximeter waveform.
In the process of determining oxygen saturation, the pulse oximeter functions as a photoelectric plethysmograph. By analyzing how the frequency spectrum of the pulse oximeter waveform changes over time, new clinically relevant features can be extracted. ⋯ Joint time frequency analysis of the pulse oximeter waveform can be used to determine the respiratory rate of ventilated patients and to quantify the impact of ventilation on the waveform. In addition, when applied to the pulse oximeter waveform new clinically relevant features were observed.
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J Clin Monit Comput · Feb 2006
The American Society of Neurophysiological Monitoring position statements project.
The American Society of Neurophysiological Monitoring (ASNM) is developing position statements aimed at assisting practitioners and others in making decisions regarding neurophysiological monitoring practice. This paper describes the procedures used in drafting these documents.
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J Clin Monit Comput · Feb 2006
Clinical TrialIntracerebral microdialysis and intracranial compliance monitoring of patients with traumatic brain injury.
The aims of this study were to get an impression of the relationships between intracranial compliance (IC) and Lactate/Pyruvate (L/P) ratio and temperature and L/P ratio, and to determine if patients with low IC had an increased vulnerability for the secondary insult hyperthermia (as reflected in the L/P ratio). The effects of coma treatment on the results were also studied. ⋯ These findings suggest the importance of avoiding hyperthermia in TBI patients, especially in patients with low or decreased IC (monitored or anticipated). The present technical solution seems promising for analysis of complex clinical data.
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J Clin Monit Comput · Feb 2006
Comparative StudyCorrelation between cardiac output measured by the femoral arterial thermodilution technique pulmonary arterial and that measured by contour pulse analysis in a paediatric animal model.
To evaluate the correlation between two methods for the determination of cardiac output: the femoral arterial thermodilution technique (FATD) and the arterial pulse contour analysis (PCCO) using the PiCCO catheter. ⋯ Femoral arterial thermodilution cardiac output measurements correlates well with pulse contour analysis cardiac output in this paediatric animal model.
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J Clin Monit Comput · Feb 2006
Linear model and algorithm to automatically estimate the pressure limit of pressure controlled ventilation for delivering a target tidal volume.
To theoretically assess the viability of an automatic procedure to support the anesthesiologist in properly setting mechanical ventilators when the operating conditions are switched from volume controlled to pressure controlled ventilation whilst maintaining the preset tidal volume. The procedure is based on a simple linear model of the ventilator breathing system with constant parameters and utilizes the signals gathered by the ventilator without the need to add further equipment. After a short period of stable volume controlled ventilation with the desired tidal volume, the herewith described algorithm allows the calculation of the value of pressure limit to set in pressure controlled mode which assures the previously settled tidal volume with the same breathing frequency and inspiratory-expiratory time ratio. ⋯ The proposed theoretical approach shows the viability, for adult settings, of one of the simplest mathematical model for mechanical ventilation in order to quickly and safely switch from volume controlled to pressure controlled ventilation. The algorithm could easily be in perspective implemented in the software of the ventilator providing the anesthesiologist with an indication on the value of pressure limit to set in order to safely switch ventilation mode.