Journal of clinical monitoring and computing
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J Clin Monit Comput · Aug 1999
Comparative StudyMicrostream capnograpy technology: a new approach to an old problem.
Significant technical limitations inherent in black-body infrared technology used in conventional sidestream and mainstream capnography have hindered the acceptance and growth of capnography as a monitoring tool outside the operating room environment. We describe a new technology (Microstream) for CO2 monitoring, based on molecular correlation spectroscopy, which results in a highly efficient and selective emission of a spectrum of discrete wavelengths exactly matching those for CO2 absorption. The CO2 specific emissions allow for an extremely small sample cell (15 microl), which in turn, permits the use of a very low sample flow rate (50 ml/min) without compromising waveform integrity or end-tidal CO2 accuracy. Design and technology features of the CO2 emission source, sample cell, and breath sampling circuits are described.
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J Clin Monit Comput · Aug 1999
Validation of an ultrasound scanner for determing urinary volumes in surgical patients and volunteers.
As bladder distension related to anaesthesia puts patients at risk for permanent dysfunction, peri-operative determination of bladder volume is of great importance. The aim of this study is to validate an ultrasonic imaging device for determing bladder urine volume. ⋯ The ultrasonic imaging device can be used peri-operatively to establish bladder volume, taking into account the 7% underestimation of the bladder volume.
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J Clin Monit Comput · Aug 1999
Artifact detection in the PO2 and PCO2 time series monitoring data from preterm infants.
Artifacts in clinical intensive care monitoring lead to false alarms and complicate later data analysis. Artifacts must be identified and processed to obtain clear information. In this paper, we present a method for detecting artifacts in PCO2 and PO2 physiological monitoring data from preterm infants. PATIENTS AND DATA: Monitored PO2 and PCO2 data (1 value per minute) from 10 preterm infants requiring intensive care were used for these experiments. A domain expert was used to review and confirm the detected artifact. ⋯ Based on the judgement of the expert, our detection method detects most PO2 and PCO2 artifacts and artifactual episodes in the 10 randomly selected preterm infants. The method makes little use of domain knowledge, and can be easily extended to detect artifacts in other monitoring channels.
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J Clin Monit Comput · Jul 1999
High fidelity correction of pressure signals from fluid-filled systems by harmonic analysis.
Fluid-filled systems are generally used for invasive pressure measurements in cardiology, anesthesiology and intensive care medicine. Wave reflection and attenuation cause considerable signal distortion. ⋯ High fidelity correction of pressure signals from fluid-filled systems by harmonic analysis is feasible.
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J Clin Monit Comput · Jul 1999
Evaluation of a new fibre-optical monitor for respiratory rate monitoring.
To present further development of a fibre-optical respiratory rate monitor and evaluate the function in the final version. ⋯ The fibre-optical monitor has sufficient accuracy for clinical monitoring. It is easy to use and inexpensive. Combinations with pulse oximetry seem attractive, to use especially for application outside "high tech areas," for example when respiratory depressant drugs are used or in ambulances.