Journal of clinical monitoring
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Evaluate the accuracy of this bedside method to determine hemoglobin (Hb) concentration in general surgery over a wide range of Hb values and to determine potential sources of error. ⋯ In the surgical blood samples, the Hb concentration determined by the CO-Oximeter (HbCOOX) ranged from 5.1 to 16.7 g/dL and the Hb concentration measured by HemoCue (HbHC) from 4.7 to 16.0 g/dL. Bias (HbCOOX - HbHC) between HbCOOX and HbHC was 0.6+/-0.6 g/dL (mean +/- SD) or 5.4+/-5.0% (p < 0.001). Also in the reconstituted blood, the bias between HbCOOX and HbHC was significant (0.2+/-0.3 g/dL or 2.1+/-3.2%; p < 0.001). The microcuvette explained 68% of the variability between HbCOOX and HbHC. HemoCue thus underestimates the Hb concentration by 2-5% and exhibits a 8-10 times higher variability with only 86.4% of HbHC being within +/- 10% of HbCOOX. CONCLUSION. Although the mean bias between HbCOOX and HbHC was relatively low, Hb measurement by HemoCue exhibited a significant variability. Loading multiple microcuvettes and averaging the results may increase the accuracy of Hb measurement by HemoCue.
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To design and implement the logistics of accommodating a large number of participants in individual, hands-on sessions on a full-scale patient simulator during a major scientific meeting or continuing medical education course. ⋯ We have developed a practical and viable method that can be adapted for use at scientific meetings and courses, which improves accessibility of individual, hands-on sessions on full-scale patient simulators to a larger audience than previously attainable. Our method is applicable for continuing medical education courses as well as research purposes in the form of prospective studies during scientific meetings and courses.
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Physiologic data measured in the clinical environment is frequently corrupted causing erroneous data to be displayed, periods of missing information or nuisance alarms to be triggered. To date, the possibility of combining sensors with similar information to improve the quality of the extracted data has not been developed. The objective of this work is to develop a method for combining heart rate measurements from multiple sensors to obtain: (i) an estimate of heart rate that is free of artifact; (ii) a confidence value associated with every heart rate estimate which indicates the likelihood that an estimate is correct; (iii) a more accurate estimate of heart rate than is available from any individual sensor. ⋯ The method of sensor fusion presented has been documented to perform well using clinical data. Limitations of the technique and the assumptions employed are discussed as well as directions for future research.
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To determine if Robust Sensor Fusion (RSF), a method designed to fuse data from multiple sensors with redundant heart rate information can be used to improve the quality of heart rate data. To determine if the improved estimate of heart rate can reduce the number of false and missed heart rate alarms. ⋯ Redundancy in sensor measurements can be used to improve HR estimation in the clinical setting. Methods like RSF which improve the quality of monitored data and reduce nuisance alarms will enhance the value of patient monitors to clinicians.
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The passage of volatile anesthetic agents through accidentally dried CO2 absorbents in anesthesia circuits can result in the chemical breakdown of anesthetics with production of greater than 10000 ppm carbon monoxide (CO). This study was designed to evaluate a portable CO monitor in the presence of volatile anesthetic agents. ⋯ Decrease in measured concentration of the sequestered samples suggests destruction of the sample by the sensor, whereas a diffusion limitation is suggested by the dependency of measured value upon flow. Any value over 500 ppm must be assumed to represent dangerous concentrations of CO because of the non-linear response of these monitors at very high CO concentrations. These portable electrochemical CO monitors are adequate to measure CO concentrations up to 500 ppm in the presence of typical clinical concentrations of anesthetics.