System Upgrade on Tue, May 28th, 2024 at 2am (EDT)
Existing users will be able to log into the site and access content. However, E-commerce and registration of new users may not be available for up to 12 hours.For online purchase, please visit us again. Contact us at customercare@wspc.com for any enquiries.
Results: 1 - 2of2
Save this search
Please login to be able to save your searches and receive alerts for new content matching your search criteria.
Analyzing thoracic cavity gas during pneumothorax treatment to monitor the pneumothorax conditions in real time for updating the treatment strategy: A pilot study
Preview AbstractObjectivesTo monitor the pneumothorax conditions in real time by analyzing thoracic cavity gas during pneumothorax treatment, and provide instructions for updating the treatment strategy.MethodsThe partial pressures of O2 and CO2 in the thoracic cavity from 49 pneumothorax patients was analyzed before the management and after chest tube clogging during the management. The pneumothorax type was differentially diagnosed according to the partial pressure results, and the treatment strategy was updated accordingly.ResultsThe 49 pneumothorax patients were divided into four groups, as follows: Group A, 30 patients with a closed pneumothorax were confirmed to have a closed pneumothorax in the second analysis; Group B, 10 patients with an open pneumothorax were confirmed to have an open pneumothorax in the second analysis; Group C, three patients with a tension pneumothorax confirmed to have a tension pneumothorax in the second analysis; and Group D, six patients with a closed pneumothorax were re-diagnosed to have an open pneumothorax in the second analysis. The cure rates of the four groups after treatment were as follows: Group A (97%, 29/30), Group B (100%, 16/16), Group C (100%, 3/3) and Group D (100%, 6/6).ConclusionsAnalyzing thoracic cavity gas during pneumothorax treatment is suggested as an efficient way to monitor the pneumothorax conditions in real time and to provide instructions for updating the treatment strategy.Modelling of the dynamic gravimetric preparation of calibration gas mixtures using permeation for trace gas analysis
Preview AbstractPermeation is a technique for realising a primary measurement standard for gas composition. A permeation tube is suspended in a permeation chamber and emits a constant mass flow of the nominally pure substance contained in it. This flow is combined with a flow of a carrier gas to obtain a calibration gas mixture with known composition. We used an automated weighing system to monitor the mass loss of the tube, and prepared mixtures of ammonia (NH3) in nitrogen. The advantage of such dynamic gas standards is that unlike static standards they do not have stability issues and the composition of the calibration gas mixture can be chosen more rapidly than with static mixtures.
We revisited and extended existing measurement models describing the standard. We show how dependencies between the input quantities in the extended model can be taken into account. We describe the effect of temperature fluctuations on the permeation rate, temperature and pressure effects on the dispersion of the weighing data. For evaluating the linearity of the balance, a simple Bayesian model was established that takes into account the repeatability and resolution of the balance. We also show that the use of ordinary least squares regression to obtain the permeation rate is justified.