scholarly journals When Resources Are Scarce - Feasibility of Emergency Ventilation of Two Patients With One Ventilator

2020 ◽  
Author(s):  
Peter C. Reinacher ◽  
Thomas E. Schlaepfer ◽  
Martin A. Schick ◽  
Jürgen Beck ◽  
Hartmut Bürkle ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Respiratory System ◽  
Breathing Circuit ◽  
Absolute Error ◽  
Physical Models ◽  
Respiratory System Mechanics ◽  
Emergency Ventilation ◽  
Artificial Lungs ◽  
Circuit Components ◽  
The Individual

AbstractA potential shortage of intensive care ventilators has led to the idea to ventilate more than one patient with a single ventilator. Besides other problems, this is associated with the lack of knowledge concerning distribution of tidal volume and the patients’ individual respiratory system mechanics.In this study we used two simple hand-manufactured adaptors to connect physical models of two adult respiratory systems to one ventilator. The artificial lungs were ventilated in the pressure-controlled mode and we investigated if disconnecting one lung from the ventilation circuit for several breaths would allow to determine reliably the other lung’s tidal volume and compliance.Compliances and volumes were measured both with the ventilator and external sensors corresponded well. However, tidal volumes measured via the ventilator were smaller compared to the tidal volumes measured via the external sensors with an absolute error of 5.3 ± 2.5%. The tidal volumes of the individual artificial lungs were distributed in proportion to the compliances and did not differ relevantly when both artificial lungs were connected to when one was disconnected.We conclude that in case of emergency, ventilation of two patients with one ventilator requires two simple hand-crafted tubes as adaptors and available standard breathing circuit components. In such a setting, respiratory system mechanics and tidal volume of each individual patient can be reliably measured during short term clamping of the tracheal tube of the respective other patient.

scholarly journals Respiratory Function in Normal Singleton Pregnancy, Multifetal Gestation and Polyhydramnios

2011 ◽  
Vol 3 (2) ◽  
pp. 78-81 ◽  
Author(s):  
Susmita Kundu ◽  
Shyamal Dasgupta ◽  
Gayetri Koppolu ◽  
Tarun Kumar Ghosh ◽  
Amitava Mukherjee ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Respiratory System ◽  
Early Pregnancy ◽  
Normal Pregnancy ◽  
Volume Measurement ◽  
Inspiratory Capacity ◽  
Singleton Pregnancy ◽  
Functional Changes ◽  
Significant Difference ◽  
The Individual

ABSTRACT Study of respiratory functions of four groups of women Nonpregnant, early pregnancy, singleton pregnancy at 36 weeks and twin/ polyhydramnios at 36 weeks reveal that inspiratory capacity (IC), tidal volume (TV) and expiratory reserve volume (ERV) in different group pairing have statistically significant difference. This is very important during the assessment of pregnant mother suffering from respiratory or cardiopulmonary disorder. Objectives This study aims to observe the additional demands placed on the maternal respiratory system in cases of advanced normal pregnancy or over distended uterus, like multifetal gestation and polyhydramnios, and whether the average Indian woman is able to cope with these respiratory changes. Methods Around 80 women were divided into four equal groups which included non-pregnant controls, normal early pregnancy (< 20 weeks), normal singleton pregnancy at 36 weeks and multifetal gestation/polyhydramnios, underwent spirometry for static lung volume measurement. The overall comparison was done by using the Kruskal-Wallis test whereas the individual comparison by Mann-Whitney test. Final statistical computing was performed with SPSS statistical package. Results The groups were comparable on the basis of age, height and hemoglobin levels. Comparisons of various groups show statistically significant difference in tidal volume, inspiratory capacity and expiratory reserve volume specially in advance pregnancy with control nonpregnant mothers without significant adverse effect on respiratory system. Conclusions Results of the study indicate that though there are significant respiratory functional changes, healthy women, even having twin/polyhydramnios, can tolerate this well. But this knowledge is very important to assess and to formulate management of pregnant women with respiratory or cardiopulmonary compromise.

RESPIRATORY FUNCTION IN NORMAL SINGLETON PREGNANCY, MULTIFETAL GESTATION AND POLYHYDRAMNIOS

2021 ◽  
pp. 27-29
Author(s):  
Chetna Chetna ◽  
Kumari Kanak Lata ◽  
Abha Rani Sinha ◽  
Debarshi Jana
Keyword(s):  
Tidal Volume ◽  
Respiratory System ◽  
Early Pregnancy ◽  
Normal Pregnancy ◽  
Volume Measurement ◽  
Inspiratory Capacity ◽  
Singleton Pregnancy ◽  
Functional Changes ◽  
Individual Comparison ◽  
The Individual

Background : Study of respiratory functions of four groups of women: Nonpregnant, early pregnancy, singleton pregnancy at 36 weeks and twin/polyhydramnios at 36 weeks reveal that inspiratory capacity (IC), tidal volume (TV) and expiratory reserve volume (ERV) in different group pairing have statistically signicant difference. This is very important during the assessment of pregnant mother suffering from respiratory or cardiopulmonary disorder. Objectives :This study aims to observe the additional demands placed on the maternal respiratory system in cases of advanced normal pregnancy or over distended uterus, like multifetal gestation and polyhydramnios, and whether the average Indian woman is able to cope with these respiratory changes. Methods : Around 80 women were divided into four equal groups which included non-pregnant controls, normal early pregnancy (< 20 weeks), normal singleton pregnancy at 36 weeks and multifetal gestation/polyhydramnios, underwent spirometry for static lung volume measurement. The overall comparison was done by using the Kruskal-Wallis test whereas the individual comparison by Mann-Whitney test. Final statistical computing was performed with SPSS statistical package. Results : The groups were comparable on the basis of age, height and hemoglobin levels. Comparisons of various groups show statistically signicant difference in tidal volume, inspiratory capacity and expiratory reserve volume specially in advance pregnancy with control nonpregnant mothers without signicant adverse effect on respiratory system. Conclusions : Results of the study indicate that though there are signicant respiratory functional changes, healthy women, even having twin/polyhydramnios, can tolerate this well. But this knowledge is very important to assess and to formulate management of pregnant women with respiratory or cardiopulmonary compromise.

scholarly journals Seeking Consensus: A New Approach

2010 ◽  
Vol 138 (12) ◽  
pp. 4402-4415 ◽  
Author(s):  
Paul J. Roebber
Keyword(s):  
Minimum Temperature ◽  
Forecast Accuracy ◽  
Cost Savings ◽  
Absolute Error ◽  
Electricity Production ◽  
Forecast Errors ◽  
Consensus Forecasts ◽  
Temperature Forecast ◽  
Model Output Statistics ◽  
The Individual

Abstract Simulated evolution is used to generate consensus forecasts of next-day minimum temperature for a site in Ohio. The evolved forecast algorithm logic is interpretable in terms of physics that might be accounted for by experienced forecasters, but the logic of the individual algorithms that form the consensus is unique. As a result, evolved program consensus forecasts produce substantial increases in forecast accuracy relative to forecast benchmarks such as model output statistics (MOS) and those from the National Weather Service (NWS). The best consensus produces a mean absolute error (MAE) of 2.98°F on an independent test dataset, representing a 27% improvement relative to MOS. These results translate to potential annual cost savings for electricity production in the state of Ohio of the order of $2 million relative to the NWS forecasts. Perfect forecasts provide nearly $6 million in additional annual electricity production cost savings relative to the evolved program consensus. The frequency of outlier events (forecast busts) falls from 24% using NWS to 16% using the evolved program consensus. Information on when busts are most likely can be provided through a logistic regression equation with two variables: forecast wind speed and the deviation of the NWS minimum temperature forecast from persistence. A forecast of a bust is 4 times more likely to be correct than wrong, suggesting some utility in anticipating the most egregious forecast errors. Discussion concerning the probabilistic applications of evolved programs, the application of this technique to other forecast problems, and the relevance of these findings to the future role of human forecasting is provided.

scholarly journals Semi-Siamese U-Net for separation of lung and heart bioimpedance images: A simulation study of thorax EIT

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246071
Author(s):  
Yen-Fen Ko ◽  
Kuo-Sheng Cheng
Keyword(s):  
Mean Absolute Error ◽  
Lung Ventilation ◽  
Semantic Segmentation ◽  
Absolute Error ◽  
Similarity Coefficient ◽  
Dice Similarity Coefficient ◽  
Linear Transformations ◽  
Impedance Tomography ◽  
Performance Improvements ◽  
The Individual

Electrical impedance tomography (EIT) is widely used for bedside monitoring of lung ventilation status. Its goal is to reflect the internal conductivity changes and estimate the electrical properties of the tissues in the thorax. However, poor spatial resolution affects EIT image reconstruction to the extent that the heart and lung-related impedance images are barely distinguishable. Several studies have attempted to tackle this problem, and approaches based on decomposition of EIT images using linear transformations have been developed, and recently, U-Net has become a prominent architecture for semantic segmentation. In this paper, we propose a novel semi-Siamese U-Net specifically tailored for EIT application. It is based on the state-of-the-art U-Net, whose structure is modified and extended, forming shared encoder with parallel decoders and has multi-task weighted losses added to adapt to the individual separation tasks. The trained semi-Siamese U-Net model was evaluated with a test dataset, and the results were compared with those of the classical U-Net in terms of Dice similarity coefficient and mean absolute error. Results showed that compared with the classical U-Net, semi-Siamese U-Net exhibited performance improvements of 11.37% and 3.2% in Dice similarity coefficient, and 3.16% and 5.54% in mean absolute error, in terms of heart and lung-impedance image separation, respectively.

New evidence for the life habit of graptoloids from physical modelling

Paleobiology ◽  
1989 ◽  
Vol 15 (4) ◽  
pp. 402-413 ◽  
Author(s):  
Susan Rigby ◽  
Barrie Rickards
Keyword(s):  
Narrow Band ◽  
Physical Modelling ◽  
Physical Models ◽  
Life Habit ◽  
Passive Rotation ◽  
Directional Motion ◽  
Mode Of Life ◽  
The Individual ◽  
New Evidence ◽  
Colony Shape

Physical models of graptolites have been constructed for a range of morphologies, with emphasis on planar, multiramous forms. The models are life size and have the density of a living graptolite, based on the now-established collagenous nature of the periderm and unavoidable assumptions about the amount of extrathecal tissue present in the living colony. These models have been used to test the two main hypotheses of graptolite life habit developed by Bulman, Rickards, Kirk, and others. Testing of graptoloid models in water suggests that many rhabdosome shapes were designed for passive rotation within the water column. This is caused in the models by a variety of modifications, including changes in thecal and stipe orientation, alterations of colony shape and the addition of vanes and hooks. Rotation would only have been useful when the rhabdosome was in directional motion and the frequency of such modifications seems anomalous if no such movement occurred. Thus movement by some means is required, either passively, by changes in buoyancy, or by automobility. Spiralling action would increase the harvesting path of an individual living on a planar, multiramous colony, making this a theoretically advantageous mode of life for the morphology. It would prevent the individual zooids of scandent biserial and uniserial colonies from feeding from the same narrow band of water.

Effect of Lowering Tidal Volume on Mortality in ARDS Varies with Respiratory System Elastance

2021 ◽  
Author(s):  
Ewan C Goligher ◽  
Eduardo L.V. Costa ◽  
Christopher J. Yarnell ◽  
Laurent J Brochard ◽  
Thomas E. Stewart ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Respiratory System
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