WorldWideScience

Sample records for hb-line ventilation instrumentation

  1. RESULTS OF EXPERIMENT TO DETERMINE CORROSION RATES FOR 304L IN HB-LINE DISSOLVER VESSEL VENTILATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J; Kathryn Counts, K

    2008-02-22

    Radioactive material being processed as part of the DE3013 program for HB-Line will result in the presence of chlorides, and in some cases fluorides, in the dissolver. Material Science and Technology developed an experimental plan to evaluate the impact of chloride on corrosion of the dissolver vessel ventilation system. The plan set test variables from the proposed operating parameters, previous test results, and a desired maximum chloride concentration for processing. The test variables included concentrations of nitric acid, fluorides and chlorides, and the presence of a welded and stressed metal coupon. Table 1 contains expected general corrosion rates in the HB-Line vessel vent system from dissolution of 3013 contents of varying nitric acid and chloride content. These general corrosion rates were measured upstream of the condenser in the experiment's offgas system near the entrance to the dissolver. However, they could apply elsewhere in the offgas system, depending on factors not simulated in the testing, including offgas system temperatures and airflow. Localized corrosion was significant in Tests One, Two, and Three. This corrosion is significant because it will probably be the first mode of penetration of the 304L steel in several places in the system. See Table 2. For Tests One and Three, the penetration rate of localized corrosion was much higher than that for general corrosion. It was approximately four times higher in Test One and at least 45 times higher in Test Three, penetrating an entire coupon thickness of 54 mils in 186 hours or less. There was no significant difference in corrosion between welded areas and un-welded areas on coupons. There was also no significant attack on stressed portions of coupons. It is probable that the lack of corrosion was because the stressed areas were facing downwards and offered no place for condensation or deposits to form. Had deposits formed, pitting may have occurred and led to stress corrosion cracking. The

  2. HB-Line Plutonium Oxide Data Collection Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, R. [Savannah River Nuclear Solutions; Varble, J. [Savannah River Nuclear Solutions; Jordan, J. [Savannah River Nuclear Solutions

    2015-05-26

    HB-Line and H-Canyon will handle and process plutonium material to produce plutonium oxide for feed to the Mixed Oxide Fuel Fabrication Facility (MFFF). However, the plutonium oxide product will not be transferred to the MFFF directly from HB-Line until it is packaged into a qualified DOE-STD-3013-2012 container. In the interim, HB-Line will load plutonium oxide into an inner, filtered can. The inner can will be placed in a filtered bag, which will be loaded into a filtered outer can. The outer can will be loaded into a certified 9975 with getter assembly in compliance with onsite transportation requirement, for subsequent storage and transfer to the K-Area Complex (KAC). After DOE-STD-3013-2012 container packaging capabilities are established, the product will be returned to HB-Line to be packaged into a qualified DOE-STD-3013-2012 container. To support the transfer of plutonium oxide to KAC and then eventually to MFFF, various material and packaging data will have to be collected and retained. In addition, data from initial HB-Line processing operations will be needed to support future DOE-STD-3013-2012 qualification as amended by the HB-Line DOE Standard equivalency. As production increases, the volume of data to collect will increase. The HB-Line data collected will be in the form of paper copies and electronic media. Paper copy data will, at a minimum, consist of facility procedures, nonconformance reports (NCRs), and DCS print outs. Electronic data will be in the form of Adobe portable document formats (PDFs). Collecting all the required data for each plutonium oxide can will be no small effort for HB-Line, and will become more challenging once the maximum annual oxide production throughput is achieved due to the sheer volume of data to be collected. The majority of the data collected will be in the form of facility procedures, DCS print outs, and laboratory results. To facilitate complete collection of this data, a traveler form will be developed which

  3. Spectrophotometers for plutonium monitoring in HB-line

    Energy Technology Data Exchange (ETDEWEB)

    Lascola, R. J. [Savannah River Site (SRS), Aiken, SC (United States); O' Rourke, P. E. [Savannah River Site (SRS), Aiken, SC (United States); Kyser, E. A. [Savannah River Site (SRS), Aiken, SC (United States); Immel, D. M. [Savannah River Site (SRS), Aiken, SC (United States); Plummer, J. R. [Savannah River Site (SRS), Aiken, SC (United States); Evans, E. V. [Savannah River Site (SRS), Aiken, SC (United States)

    2016-02-12

    This report describes the equipment, control software, calibrations for total plutonium and plutonium oxidation state, and qualification studies for the instrument. It also provides a detailed description of the uncertainty analysis, which includes source terms associated with plutonium calibration standards, instrument drift, and inter-instrument variability. Also included are work instructions for instrument, flow cell, and optical fiber setup, work instructions for routine maintenance, and drawings and schematic diagrams.

  4. Determination of filter pore size for use in HB line phase II production of plutonium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Shehee, T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Crowder, M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rudisill, T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-08-01

    H-Canyon and HB-Line are tasked with the production of plutonium oxide (PuO2) from a feed of plutonium (Pu) metal. The PuO2 will provide feed material for the Mixed Oxide (MOX) Fuel Fabrication Facility. After dissolution of the Pu metal in H-Canyon, plans are to transfer the solution to HB-Line for purification by anion exchange. Anion exchange will be followed by plutonium(IV) oxalate precipitation, filtration, and calcination to form PuO2. The filtrate solutions, remaining after precipitation, contain low levels of Pu ions, oxalate ions, and may include solids. These solutions are transferred to H-Canyon for disposition. To mitigate the criticality concern of Pu solids in a Canyon tank, past processes have used oxalate destruction or have pre-filled the Canyon tank with a neutron poison. The installation of a filter on the process lines from the HB-Line filtrate tanks to H-Canyon Tank 9.6 is proposed to remove plutonium oxalate solids. This report describes SRNL’s efforts to determine the appropriate pore size for the filters needed to perform this function. Information provided in this report aids in developing the control strategies for solids in the process.

  5. Capability to Recover Plutonium-238 in H-Canyon/HB-Line - 13248

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Kenneth S. Jr.; Smith, Robert H. Jr.; Goergen, Charles R. [Savannah River Nuclear Solutions, LLC, Savannah River Site, Aiken, SC 29802 (United States)

    2013-07-01

    Plutonium-238 is used in Radioisotope Thermoelectric Generators (RTGs) to generate electrical power and in Radioisotope Heater Units (RHUs) to produce heat for electronics and environmental control for deep space missions. The domestic supply of Pu-238 consists of scrap material from previous mission production or material purchased from Russia. Currently, the United States has no significant production scale operational capability to produce and separate new Pu-238 from irradiated neptunium-237 targets. The Department of Energy - Nuclear Energy is currently evaluating and developing plans to reconstitute the United States capability to produce Pu-238 from irradiated Np-237 targets. The Savannah River Site had previously produced and/or processed all the Pu-238 utilized in Radioisotope Thermoelectric Generators (RTGs) for deep space missions up to and including the majority of the plutonium for the Cassini Mission. The previous full production cycle capabilities included: Np- 237 target fabrication, target irradiation, target dissolution and Np-237 and Pu-238 separation and purification, conversion of Np-237 and Pu-238 to oxide, scrap recovery, and Pu-238 encapsulation. The capability and equipment still exist and could be revitalized or put back into service to recover and purify Pu-238/Np-237 or broken General Purpose Heat Source (GPHS) pellets utilizing existing process equipment in HB-Line Scrap Recovery, and H-Canyon Frame Waste Recovery processes. The conversion of Np-237 and Pu-238 to oxide can be performed in the existing HB-Line Phase-2 and Phase- 3 Processes. Dissolution of irradiated Np-237 target material, and separation and purification of Np-237 and Pu-238 product streams would be possible at production rates of ∼2 kg/month of Pu-238 if the existing H-Canyon Frames Process spare equipment were re-installed. Previously, the primary H-Canyon Frames equipment was removed to be replaced: however, the replacement project was stopped. The spare equipment

  6. Efficiency of lung ventilation for people performing wind instruments

    Directory of Open Access Journals (Sweden)

    Anna Brzęk

    2016-08-01

    Full Text Available Background: Wind instruments musicians are particularly prone to excessive respiratory efforts. Prolonged wind instruments performing may lead to changes in respiratory tracts and thus to respiratory muscles overload. It may result in decreasing lung tissue pliability and, as a consequence, in emphysema. Aim of the research has been to describe basic spirometric parameters for wind players and causes of potential changes. Material and Methods: Slow and forced spirometry with the use of Micro Lab Viasys (Micro Medical, Great Britain was conducted on 31 wind musicians (group A. A survey concerning playing time and frequency, weight of instruments, and education on diaphragmatic breathing was conducted. The control group included 34 healthy persons at similar age (group B. The results were statistically described using Excel and Statistica programmes. Results: The respiratory parameters were within the range of physiological norms and forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC exceeded in both groups the values of 100%. Forced vital capacity and expiratory vital capacity (EVC values were significantly lower in the group of musicians than in the control group (p < 0.001. In 45% the group A used diaphragmatic breathing, in 31% of examinees mixed respiratory tract was observed. The significant discrepancy of individual parameters was obtained regarding age and the length of time when performing wind instrument. Conclusions: Spirometric parameters relative to standards may prove a good respiratory capacity. Peak expiratory flow (PEF and FEV1 may indicate that a proper technique of respiration during performance was acquired. The length of time when performing wind instrument may influence parameters of dynamic spirometry. Med Pr 2016;67(4:427–433

  7. Instrumentation strategies for energy conservation in broiler barns with ventilation air solar pre-heaters

    Energy Technology Data Exchange (ETDEWEB)

    Cordeau, Sebastien; Barrington, Suzelle [Department of Bioresource Engineering, Macdonald Campus of McGill University, 21 111 Lakeshore, Ste Anne de Bellevue, Quebec H9X 3V9 (Canada)

    2010-08-15

    At the present consumption rate, world fossil-fuel reserves are expected to be depleted by 2050 unless their consumption is optimized and supplemented with renewable energy sources. The objective of this project was to evaluate the performance of a simple data acquisition system installed to conduct an energy balance and identify energy saving strategies in two commercial broilers barns with ventilation air solar pre-heaters. Located near Montreal, Canada, the two identical barns were instrumented for inside and outside air conditions, ventilation rate and energy recovery by the solar air pre-heaters. Whereas the temperature, relative humidity and radiation sensors were reliable, inside air temperature stratification complicated energy balance analyses and broiler heat production rate calculations. Lack of room air mixing resulted in the loss of 25 and 15% of the generated heater load and recovered solar energy. The proper monitoring of all environmental conditions required their measurement every 5 rather than 20 min. Instead of using a data transmission service found to be unreliable in rural areas, all data loggers were downloaded onto a portable computer every 45 days during regular instrument maintenance. Accordingly, room air mixing is recommended to facilitate energy balance studies and improve the efficient use of heating energies. (author)

  8. Investigation Of In-Line Monitoring Options At H Canyon/HB Line For Plutonium Oxide Production

    Energy Technology Data Exchange (ETDEWEB)

    Sexton, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-14

    H Canyon and HB Line have a production goal of 1 MT per year of plutonium oxide feedstock for the MOX facility by FY17 (AFS-2 mission). In order to meet this goal, steps will need to be taken to improve processing efficiency. One concept for achieving this goal is to implement in-line process monitoring at key measurement points within the facilities. In-line monitoring during operations has the potential to increase throughput and efficiency while reducing costs associated with laboratory sample analysis. In the work reported here, we mapped the plutonium oxide process, identified key measurement points, investigated alternate technologies that could be used for in-line analysis, and initiated a throughput benefit analysis.

  9. Environmental assessment operation of the HB-Line facility and frame waste recovery process for production of Pu-238 oxide at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-01

    The Department of Energy (DOE) has prepared an environmental assessment (EA), DOE/EA-0948, addressing future operations of the HB-Line facility and the Frame Waste Recovery process at the Savannah River Site (SRS), near Aiken, South Carolina. Based on the analyses in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, DOE has concluded that, the preparation of an environmental impact statement is not required, and is issuing this Finding of No Significant Impact.

  10. TECHNICAL BASIS FOR DOE STANDARD 3013 EQUIVALENCY SUPPORTING REDUCED TEMPERATURE STABILIZATION OF OXALATE-DERIVED PLUTONIUM OXIDE PRODUCED BY THE HB-LINE FACILITY AT SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Duffey, J.; Livingston, R.; Berg, J.; Veirs, D.

    2012-07-02

    The HB-Line (HBL) facility at the Savannah River Site (SRS) is designed to produce high-purity plutonium dioxide (PuO{sub 2}) which is suitable for future use in production of Mixed Oxide (MOX) fuel. The MOX Fuel Fabrication Facility (MFFF) requires PuO{sub 2} feed to be packaged per the U.S. Department of Energy (DOE) Standard 3013 (DOE-STD-3013) to comply with the facility's safety basis. The stabilization conditions imposed by DOE-STD-3013 for PuO{sub 2} (i.e., 950 C for 2 hours) preclude use of the HBL PuO{sub 2} in direct fuel fabrication and reduce the value of the HBL product as MFFF feedstock. Consequently, HBL initiated a technical evaluation to define acceptable operating conditions for production of high-purity PuO{sub 2} that fulfills the DOE-STD-3013 criteria for safe storage. The purpose of this document is to demonstrate that within the defined operating conditions, the HBL process will be equivalent for meeting the requirements of the DOE-STD-3013 stabilization process for plutonium-bearing materials from the DOE complex. The proposed 3013 equivalency reduces the prescribed stabilization temperature for high-purity PuO{sub 2} from oxalate precipitation processes from 950 C to 640 C and places a limit of 60% on the relative humidity (RH) at the lowest material temperature. The equivalency is limited to material produced using the HBL established flow sheet, for example, nitric acid anion exchange and Pu(IV) direct strike oxalate precipitation with stabilization at a minimum temperature of 640 C for four hours (h). The product purity must meet the MFFF acceptance criteria of 23,600 {micro}g/g Pu (i.e., 2.1 wt %) total impurities and chloride content less than 250 {micro}g/g of Pu. All other stabilization and packaging criteria identified by DOE-STD-3013-2012 or earlier revisions of the standard apply. Based on the evaluation of test data discussed in this document, the expert judgment of the authors supports packaging the HBL product under a 3013

  11. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2001-04-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor.

  12. Instruments

    Energy Technology Data Exchange (ETDEWEB)

    Buehrer, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-12-31

    The present paper mediates a basic knowledge of the most commonly used experimental techniques. We discuss the principles and concepts necessary to understand what one is doing if one performs an experiment on a certain instrument. (author) 29 figs., 1 tab., refs.

  13. Displacement ventilation

    DEFF Research Database (Denmark)

    Kosonen, Risto; Melikov, Arsen Krikor; Mundt, Elisabeth

    The aim of this Guidebook is to give the state-of-the art knowledge of the displacement ventilation technology, and to simplify and improve the practical design procedure. The Guidebook discusses methods of total volume ventilation by mixing ventilation and displacement ventilation and it gives...... insights of the performance of the displacement ventilation. It also shows practical case studies in some typical applications and the latest research findings to create good local micro-climatic conditions....

  14. Demand Controlled Ventilation and Classroom Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  15. Demand controlled ventilation and classroom ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mendell, Mark J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Davies, Molly [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Eliseeva, Ekaterina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Faulkner, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hong, Tienzen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sullivan, Douglas P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling.

  16. Displacement Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    Displacement ventilation is an interesting new type of air distribution principle which should be considered in connection with design of comfort ventilation in both smal1 and large spaces. Research activities on displacement ventilation are large all over the world and new knowledge of design...... methods appears continuously. This book gives an easy introduction to the basis of displacement ventilation and the chapters are written in the order which is used in a design procedure. The main text is extended by five appendices which show some of the new research activities taking place at Aalborg...

  17. Ventilative Cooling

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols; Kolokotroni, Maria

    -of-the-art of ventilative cooling potentials and limitations, its consideration in current energy performance regulations, available building components and control strategies and analysis methods and tools. In addition, the report provides twenty six examples of operational buildings using ventilative cooling ranging from...

  18. Ventilation Effectiveness

    DEFF Research Database (Denmark)

    Mundt, M.; Mathisen, H. M.; Moser, M.

    Improving the ventilation effectiveness allows the indoor air quality to be significantly enhanced without the need for higher air changes in the building, thereby avoiding the higher costs and energy consumption associated with increasing the ventilation rates. This Guidebook provides easy...

  19. Liquid Ventilation

    Directory of Open Access Journals (Sweden)

    Qutaiba A. Tawfic

    2011-01-01

    Full Text Available Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future. Keywords: Liquid ventilation; perfluorochemicals; perfluorocarbon; respiratory distress; surfactant.

  20. Ventilator graphics.

    Science.gov (United States)

    Prabhakaran, Priya; Sasser, William C; Kalra, Yuvrai; Rutledge, Chrystal; Tofil, Nancy M

    2016-12-01

    Providing optimal mechanical ventilation to critically-ill children remains a challenge. Patient-ventilator dyssynchrony results frequently with numerous deleterious consequences on patient outcome including increased requirement for sedation, prolonged duration of ventilation, and greater imposed work of breathing. Most currently used ventilators have real-time, continuously-displayed graphics of pressure, volume, and flow versus time (scalars) as well as pressure, and flow versus volume (loops). A clear understanding of these graphics provides a lot of information about the mechanics of the respiratory system and the patient ventilator interaction in a dynamic fashion. Using this information will facilitate tailoring the support provided and the manner in which it is provided to best suit the dynamic needs of the patient. This paper starts with a description of the scalars and loops followed by a discussion of the information that can be obtained from each of these graphics. A review will follow, on the common types of dyssynchronous interactions and how each of these can be detected on the ventilator graphics. The final section discusses how graphics can be used to optimize the ventilator support provided to patients.

  1. Mechanical Ventilation

    Science.gov (United States)

    ... cared for in a hospital’s intensive care unit (ICU). People who need a ventilator for a longer time may be in a regular unit of a hospital, a rehabilitation facility, or cared for at home. Why are ...

  2. Personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2004-01-01

    The thermal environment and air quality in buildings affects occupants' health, comfort and performance. The heating, ventilating and air-conditioning (HVAC) of buildings today is designed to provide a uniform room environment. However, large individual differences exist between occupants in regard...... microenvironment. Furthermore, HVAC systems should be designed to protect occupants from airborne transmission of infectious agents that may be present in exhaled air. Personalized ventilation is a new development in the field of HVAC and has the potential to fulfill the above requirements. This paper reviews...... existing knowledge on performance of personalized ventilation (PV) and on human response to it. The airflow interaction in the vicinity of the human body is analyzed and its impact on thermal comfort and inhaled air quality is discussed together with control strategies and the application of PV in practice...

  3. Personalized ventilation.

    Science.gov (United States)

    Melikov, A K

    2004-01-01

    The thermal environment and air quality in buildings affects occupants' health, comfort and performance. The heating, ventilating and air-conditioning (HVAC) of buildings today is designed to provide a uniform room environment. However, large individual differences exist between occupants in regard to physiological and psychological response, clothing insulation, activity, air temperature and air movement preference, etc. Environmental conditions acceptable for most occupants in rooms may be achieved by providing each occupant with the possibility to generate and control his/her own preferred microenvironment. Furthermore, HVAC systems should be designed to protect occupants from airborne transmission of infectious agents that may be present in exhaled air. Personalized ventilation is a new development in the field of HVAC and has the potential to fulfill the above requirements. This paper reviews existing knowledge on performance of personalized ventilation (PV) and on human response to it. The airflow interaction in the vicinity of the human body is analyzed and its impact on thermal comfort and inhaled air quality is discussed together with control strategies and the application of PV in practice. Performance criteria are defined. Recommendations for design of PV that would be in compliance with the criteria are given. Future research needed on the topic is outlined. Personalized ventilation can improve occupants' comfort, decrease SBS symptoms and reduce the risk of transmission of contagion between occupants in comparison with total volume ventilation. However in order to perform efficiently in rooms in practice, the design (air distribution, control, etc.) has to be carefully considered together with type of occupant activity (occupancy rate, occupied density, etc.).

  4. Displacement Ventilation

    DEFF Research Database (Denmark)

    Bjørn, Erik; Mattsson, Magnus; Sandberg, Mats

    Full-scale experiments were made in a displacement ventilated room with two breathing thermal manikins to study the effect of movements and breathing on the vertical contaminant distribution, and on the personal exposure of occupants. Concentrations were measured with tracer gas equipment...... in the room and in the inhalation of both manikins. Tracer gas was added in the heat plume above a sitting manikin, or in the exhalation through either the nose or the mouth. The other manikin moved back and forth at different speeds on a low trolley. The mentioned experimental conditions have a significant...

  5. Kitchen ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, R.M. [Univ. of Tennessee, Knoxville, TN (United States). College of Architecture; Rousseau, C. [Newcomb and Boyd Consulting Engineers, Atlanta, GA (United States)

    1995-09-01

    Kitchen ventilation is a subject that has not received the attention that has been given to more glamorous HVAC and R topics. Consequently, its theoretical and technical development has not advanced like these topics. However, a group has been working within the ASHRAE Technical Committee (TC) and Task Group (TG) framework to correct this situation. The group is TG5.KV and it achieved TG status last year after starting as an informal group and then a sub-committee of TC9.8. One of its efforts has been to write a Handbook chapter, which will appear in the 1995 ASHRAE Handbook -- Applications. This article is a survey of that chapter.

  6. Emergency medicine residents' knowledge of mechanical ventilation.

    Science.gov (United States)

    Wilcox, Susan R; Seigel, Todd A; Strout, Tania D; Schneider, Jeffrey I; Mitchell, Patricia M; Marcolini, Evie G; Cocchi, Michael N; Smithline, Howard A; Lutfy-Clayton, Lucienne; Mullen, Marie; Ilgen, Jonathan S; Richards, Jeremy B

    2015-04-01

    Although Emergency physicians frequently intubate patients, management of mechanical ventilation has not been emphasized in emergency medicine (EM) residency curricula. The objective of this study was to quantify EM residents' education, experience, and knowledge regarding mechanical ventilation. We developed a survey of residents' educational experiences with ventilators and an assessment tool with nine clinical questions. Correlation and regression analyses were performed to evaluate the relationship between residents' scores on the assessment instrument and their training, education, and comfort with ventilation. Of 312 EM residents, 218 responded (69.9%). The overall correct response rate for the assessment tool was 73.3%, standard deviation (SD) ± 22.3. Seventy-seven percent (n = 167) of respondents reported ≤ 3 h of mechanical ventilation education in their residency curricula over the past year. Residents reported frequently caring for ventilated patients in the ED, as 64% (n = 139) recalled caring for ≥ 4 ventilated patients per month. Fifty-three percent (n = 116) of residents endorsed feeling comfortable caring for mechanically ventilated ED patients. In multiregression analysis, the only significant predictor of total test score was residents' comfort with caring for mechanically ventilated patients (F = 10.963, p = 0.001). EM residents report caring for mechanically ventilated patients frequently, but receive little education on mechanical ventilation. Furthermore, as residents' performance on the assessment tool is only correlated with their self-reported comfort with caring for ventilated patients, these results demonstrate an opportunity for increased educational focus on mechanical ventilation management in EM residency training. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Variable mechanical ventilation

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini Jr., Luiz Alberto; Friedman, Gilberto

    2017-01-01

    Objective To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Methods Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". Results A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Conclusion Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation. PMID:28444076

  8. VENTILATION NEEDS DURING CONSTRUCTION

    Energy Technology Data Exchange (ETDEWEB)

    C.R. Gorrell

    1998-07-23

    The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options.

  9. Variable mechanical ventilation.

    Science.gov (United States)

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini, Luiz Alberto; Friedman, Gilberto

    2017-01-01

    To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation.

  10. Variable mechanical ventilation

    OpenAIRE

    Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini Jr.,Luiz Alberto; Friedman, Gilberto

    2017-01-01

    Objective To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Methods Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE?, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". Results A total of 36 studies were selected. ...

  11. Ventilator associated pneumonia or ventilator induced pneumonia.

    Science.gov (United States)

    Khan, Zahid Hussain; Ceriana, Piero; Donner, Claudio F

    2017-01-01

    Ventilator associated pneumonia currently in vogue seems to have some pitfalls as far as the nomenclature is concerned and thus it imparts an erroneous impression to the reader. As the driving force is in fact the ventilator, the phraseology should preferably be changed to ventilator induced pneumonia to convey the in depth meaning of the term thus evading the terminology currently in practice. A new and emerging paradigm dealing with all side effects of mechanical ventilation can be helpful to solve this etymological conflict.

  12. Patient-Ventilator Dyssynchrony

    Directory of Open Access Journals (Sweden)

    Elvira-Markela Antonogiannaki

    2017-11-01

    Full Text Available In mechanically ventilated patients, assisted mechanical ventilation (MV is employed early, following the acute phase of critical illness, in order to eliminate the detrimental effects of controlled MV, most notably the development of ventilator-induced diaphragmatic dysfunction. Nevertheless, the benefits of assisted MV are often counteracted by the development of patient-ventilator dyssynchrony. Patient-ventilator dyssynchrony occurs when either the initiation and/or termination of mechanical breath is not in time agreement with the initiation and termination of neural inspiration, respectively, or if the magnitude of mechanical assist does not respond to the patient’s respiratory demand. As patient-ventilator dyssynchrony has been associated with several adverse effects and can adversely influence patient outcome, every effort should be made to recognize and correct this occurrence at bedside. To detect patient-ventilator dyssynchronies, the physician should assess patient comfort and carefully inspect the pressure- and flow-time waveforms, available on the ventilator screen of all modern ventilators. Modern ventilators offer several modifiable settings to improve patient-ventilator interaction. New proportional modes of ventilation are also very helpful in improving patient-ventilator interaction.

  13. Mechanical ventilator - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007240.htm Mechanical ventilator - infants To use the sharing features on this page, please enable JavaScript. A mechanical ventilator is a machine that assists with breathing. ...

  14. Diffuse ceiling ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen

    Diffuse ceiling ventilation is an innovative ventilation concept where the suspended ceiling serves as air diffuser to supply fresh air into the room. Compared with conventional ventilation systems, diffuse ceiling ventilation can significantly reduce or even eliminate draught risk due to the low...... momentum supply. In addition, this ventilation system uses a ceiling plenum to deliver air and requires less energy consumption for air transport than full-ducted systems. There is a growing interest in applying diffuse ceiling ventilation in offices and other commercial buildings due to the benefits from...... both thermal comfort and energy efficient aspects. The present study aims to characterize the air distribution and thermal comfort in the rooms with diffuse ceiling ventilation. Both the stand-alone ventilation system and its integration with a radiant ceiling system are investigated. This study also...

  15. Complications of mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Drašković Biljana

    2011-01-01

    Full Text Available Mechanical ventilation of the lungs, as an important therapeutic measure, cannot be avoided in critically ill patients. However, when machines take over some of vital functions there is always a risk of complications and accidents. Complications associated with mechanical ventilation can be divided into: 1 airway-associated complications; 2 complications in the response of patients to mechanical ventilation; and 3 complications related to the patient’s response to the device for mechanical ventilation. Complications of artificial airway may be related to intubation and extubation or the endotracheal tube. Complications of mechanical ventilation, which arise because of the patient’s response to mechanical ventilation, may primarily cause significant side effects to the lungs. During the last two decades it was concluded that mechanical ventilation can worsen or cause acute lung injury. Mechanical ventilation may increase the alveolar/capillary permeability by overdistension of the lungs (volutrauma, it can exacerbate lung damage due to the recruitment/derecruitment of collapsed alveoli (atelectrauma and may cause subtle damages due to the activation of inflammatory processes (biotrauma. Complications caused by mechanical ventilation, beside those involving the lungs, can also have significant effects on other organs and organic systems, and can be a significant factor contributing to the increase of morbidity and mortality in critically ill of mechanically ventilated patients. Complications are fortunately rare and do not occur in every patient, but due to their seriousness and severity they require extensive knowledge, experience and responsibility by health-care workers.

  16. ROV inspection inside ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R.E.; Street, P.F.; Cole, G.V. [AEA Technology, Harwell (United Kingdom)

    1996-12-31

    An instrumentation package for carrying out visual inspections and radiation monitoring within radioactive duct-work has been developed. This paper describes the first application of the package in the main ventilation duct of the Dounreay fuel cycle area. The package was deployed via a commerical ROV within a duct consisting of two parallel runs, over 300 metres long, between 0.9 and 1.7 metres high and 1.1 metres wide. An integrated, computer-controlled station was used for data collection, recording in digital form and on video tape. (Author).

  17. Academic Emergency Medicine Physicians’ Knowledge of Mechanical Ventilation

    Directory of Open Access Journals (Sweden)

    Susan R. Wilcox

    2016-05-01

    Full Text Available Introduction: Although emergency physicians frequently intubate patients, management of mechanical ventilation has not been emphasized in emergency medicine (EM education or clinical practice. The objective of this study was to quantify EM attendings’ education, experience, and knowledge regarding mechanical ventilation in the emergency department. Methods: We developed a survey of academic EM attendings’ educational experiences with ventilators and a knowledge assessment tool with nine clinical questions. EM attendings at key teaching hospitals for seven EM residency training programs in the northeastern United States were invited to participate in this survey study. We performed correlation and regression analyses to evaluate the relationship between attendings’ scores on the assessment instrument and their training, education, and comfort with ventilation. Results: Of 394 EM attendings surveyed, 211 responded (53.6%. Of respondents, 74.5% reported receiving three or fewer hours of ventilation-related education from EM sources over the past year and 98 (46% reported receiving between 0-1 hour of education. The overall correct response rate for the assessment tool was 73.4%, with a standard deviation of 19.9. The factors associated with a higher score were completion of an EM residency, prior emphasis on mechanical ventilation during one’s own residency, working in a setting where an emergency physician bears primary responsibility for ventilator management, and level of comfort with managing ventilated patients. Physicians’ comfort was associated with the frequency of ventilator changes and EM management of ventilation, as well as hours of education. Conclusion: EM attendings report caring for mechanically ventilated patients frequently, but most receive fewer than three educational hours a year on mechanical ventilation, and nearly half receive 0-1 hour. Physicians’ performance on an assessment tool for mechanical ventilation is

  18. Academic Emergency Medicine Physicians' Knowledge of Mechanical Ventilation.

    Science.gov (United States)

    Wilcox, Susan R; Strout, Tania D; Schneider, Jeffrey I; Mitchell, Patricia M; Smith, Jessica; Lutfy-Clayton, Lucienne; Marcolini, Evie G; Aydin, Ani; Seigel, Todd A; Richards, Jeremy B

    2016-05-01

    Although emergency physicians frequently intubate patients, management of mechanical ventilation has not been emphasized in emergency medicine (EM) education or clinical practice. The objective of this study was to quantify EM attendings' education, experience, and knowledge regarding mechanical ventilation in the emergency department. We developed a survey of academic EM attendings' educational experiences with ventilators and a knowledge assessment tool with nine clinical questions. EM attendings at key teaching hospitals for seven EM residency training programs in the northeastern United States were invited to participate in this survey study. We performed correlation and regression analyses to evaluate the relationship between attendings' scores on the assessment instrument and their training, education, and comfort with ventilation. Of 394 EM attendings surveyed, 211 responded (53.6%). Of respondents, 74.5% reported receiving three or fewer hours of ventilation-related education from EM sources over the past year and 98 (46%) reported receiving between 0-1 hour of education. The overall correct response rate for the assessment tool was 73.4%, with a standard deviation of 19.9. The factors associated with a higher score were completion of an EM residency, prior emphasis on mechanical ventilation during one's own residency, working in a setting where an emergency physician bears primary responsibility for ventilator management, and level of comfort with managing ventilated patients. Physicians' comfort was associated with the frequency of ventilator changes and EM management of ventilation, as well as hours of education. EM attendings report caring for mechanically ventilated patients frequently, but most receive fewer than three educational hours a year on mechanical ventilation, and nearly half receive 0-1 hour. Physicians' performance on an assessment tool for mechanical ventilation is most strongly correlated with their self-reported comfort with mechanical

  19. Design Principles for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system -Hybrid Ventilation. ....... The hybrid ventilation concepts, design challenges and - principles are discussed and illustrated by four building examples....

  20. Mechanical ventilation in children.

    Science.gov (United States)

    Kendirli, Tanil; Kavaz, Asli; Yalaki, Zahide; Oztürk Hişmi, Burcu; Derelli, Emel; Ince, Erdal

    2006-01-01

    Mechanical ventilation can be lifesaving, but > 50% of complications in conditions that require intensive care are related to ventilatory support, particularly if it is prolonged. We retrospectively evaluated the medical records of patients who had mechanical ventilation in the Pediatric Intensive Care Unit (PICU) during a follow-up period between January 2002-May 2005. Medical records of 407 patients were reviewed. Ninety-one patients (22.3%) were treated with mechanical ventilation. Ages of all patients were between 1-180 (median: 8) months. The mechanical ventilation time was 18.8 +/- 14.1 days. Indication of mechanical ventilation could be divided into four groups as respiratory failure (64.8%), cardiovascular failure (19.7%), central nervous system disease (9.8%) and safety airway (5.4%). Tracheostomy was performed in four patients. The complication ratio of mechanically ventilated children was 42.8%, and diversity of complications was as follows: 26.3% atelectasia, 17.5% ventilator-associated pneumonia, 13.1% pneumothorax, 5.4% bleeding, 4.3% tracheal edema, and 2.1% chronic lung disease. The mortality rate of mechanically ventilated patients was 58.3%, but the overall mortality rate in the PICU was 12.2%. In conclusion, there are few published epidemiological data on the follow-up results and mortality in infants and children who are mechanically ventilated.

  1. Natural Ventilation in Atria

    DEFF Research Database (Denmark)

    Svidt, Kjeld; Heiselberg, Per; Hendriksen, Ole Juhl

    This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions.......This case study comprises a monitoring programme as well as a Computational Fluid Dynamics (CFD) analysis of a natural ventilated atrium. The purpose has been to analyse the performance of a typical natural ventilation system in Denmark under both summer and winter conditions....

  2. VENTILATION MODEL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    V. Chipman

    2002-10-31

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses.

  3. Multifamily Ventilation Retrofit Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K.; Lstiburek, J.; Bergey, D.

    2012-12-01

    In multifamily buildings, central ventilation systems often have poor performance, overventilating some portions of the building (causing excess energy use), while simultaneously underventilating other portions (causing diminished indoor air quality). BSC and Innova Services Corporation performed a series of field tests at a mid-rise test building undergoing a major energy audit and retrofit, which included ventilation system upgrades.

  4. Ventilation rates and health

    DEFF Research Database (Denmark)

    Sundell, Jan; Levin, H; Nazaroff, W W

    2011-01-01

    The scientific literature through 2005 on the effects of ventilation rates on health in indoor environments has been reviewed by a multidisciplinary group. The group judged 27 papers published in peer-reviewed scientific journals as providing sufficient information on both ventilation rates...... and health effects to inform the relationship. Consistency was found across multiple investigations and different epidemiologic designs for different populations. Multiple health endpoints show similar relationships with ventilation rate. There is biological plausibility for an association of health outcomes...... studies of the relationship between ventilation rates and health, especially in diverse climates, in locations with polluted outdoor air and in buildings other than offices. PRACTICAL IMPLICATIONS: Ventilation with outdoor air plays an important role influencing human exposures to indoor pollutants...

  5. Ventilator waveform interpretation in mechanically ventilated small animals.

    Science.gov (United States)

    Corona, Terry M; Aumann, Marcel

    2011-10-01

    To review the topic of ventilator waveforms analysis with emphasis on interpretation of ventilator waveforms and their use in the management and monitoring of mechanically ventilated small animal patients. Human clinical studies, scientific reviews, and textbooks, as well as veterinary textbooks and clinical examples of ventilator waveforms in mechanically ventilated dogs. Ventilator waveforms are graphic representations of data collected from the ventilator and reflect patient-ventilator interactions. The 4 parameters pressure, volume, flow, and time are most descriptive of mechanical ventilation. Typically, 3 different graphs, also referred to as scalars, consisting of pressure versus time, volume versus time, and flow versus time, with time always plotted on the x-axis, are used. Changes in the ventilator settings as well as in the characteristics of the lungs such as airway resistance (R(aw)) and respiratory system compliance (C(rs)) can be recognized from specific variations in the waveforms. Flow-volume and pressure-volume loops provide additional information about changes in lung function. Patient-ventilator dyssynchrony is a common problem during mechanical ventilation and can lead to patient discomfort and an increased work of breathing. Ventilator waveforms are helpful to identify dyssynchrony, which can be divided into trigger, flow, cycle, and expiratory dyssynchrony. Ventilator waveforms allow the clinician to assess changes in respiratory mechanics, and can be useful in monitoring the progression of disease pathology and response to therapy. Adjustments in ventilator settings based on proper analysis and interpretation of these waveforms can help the clinician to optimize ventilation therapy. Ventilator waveforms are graphic representations of patient-ventilator interactions. Proper interpretation of ventilator waveforms affords the critical care clinician a better understanding of the patient's respiratory function, response to therapy, and causes

  6. Mechanical Ventilation Antioxidant Trial.

    Science.gov (United States)

    Howe, Kimberly P; Clochesy, John M; Goldstein, Lawrence S; Owen, Hugh

    2015-09-01

    Many patients each year require prolonged mechanical ventilation. Inflammatory processes may prevent successful weaning, and evidence indicates that mechanical ventilation induces oxidative stress in the diaphragm, resulting in atrophy and contractile dysfunction of diaphragmatic myofibers. Antioxidant supplementation might mitigate the harmful effects of the oxidative stress induced by mechanical ventilation. To test the clinical effectiveness of antioxidant supplementation in reducing the duration of mechanical ventilation. A randomized, prospective, placebo-controlled double-blind design was used to test whether enterally administered antioxidant supplementation would decrease the duration of mechanical ventilation, all-cause mortality, and length of stay in the intensive care unit and hospital. Patients received vitamin C 1000 mg plus vitamin E 1000 IU, vitamin C 1000 mg plus vitamin E 1000 IU plus N-acetylcysteine 400 mg, or placebo solution as a bolus injection via their enteral feeding tube every 8 hours. Clinical and statistically significant differences in duration of mechanical ventilation were seen among the 3 groups (Mantel-Cox log rank statistic = 5.69, df = 1, P = .017). The 3 groups did not differ significantly in all-cause mortality during hospitalization or in the length of stay in the intensive care unit or hospital. Enteral administration of antioxidants is a simple, safe, inexpensive, and effective intervention that decreases the duration of mechanical ventilation in critically ill adults. ©2015 American Association of Critical-Care Nurses.

  7. Chaos in Ocean Ventilation

    Science.gov (United States)

    MacGilchrist, G. A.; Marshall, D. P.; Johnson, H. L.; Lique, C.; Thomas, M. D.

    2016-02-01

    Ventilation of the subtropical ocean is important for setting the ocean stratification, the oceanic cycling of biogeochemical elements and the storage of carbon dioxide and heat on inter-annual to decadal timescales. In the textbook view, subtropical ocean ventilation is achieved through advection by the time-mean gyre circulation, with fluid parcels moving along sloping density surfaces into the ocean interior. At the same time, it is well accepted that the ocean circulation is highly nonlinear, with the kinetic energy budget dominated by mesoscale eddies. Consequently, ventilated fluid parcels, rather than remaining coherent as they move into the ocean interior, will be rapidly strained and stirred into surrounding water. To investigate the role of this nonlinear circulation in the ventilation process, we calculate a non-dimensional `filamentation number' - the ratio of the Lagrangian ventilation timescale and the timescale of strain by the nonlinear flow - across two density surfaces in the subtropical North Atlantic in an ocean circulation model. This number predicts the filament width of a ventilated fluid parcel, and is found to be large across both density surfaces (indicating small filament width), particularly on the deeper surface. A Lagrangian mapping from distributions of particles to the year in which they were ventilated is thus shown to be highly chaotic, with particles located side-by-side having been ventilated decades apart, even where the density surface is close to the ocean surface. This novel Lagrangian approach avoids the loss of information through diffusion, and emphasises the importance of mesoscale eddies in the ventilation of the subtropical ocean.

  8. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    -cooling period and night cooling potential. The investment cost of this ventilation system is about 5-10% lower than the conventional ones, because the acoustic ceiling could be directly applied as air diffuser and the use of plenum to distribute air reduces the cost of ductwork. There is a growing interest...... in applying diffuse ceiling ventilation in offices and other commercial buildings because of the benefits from both thermal comfort and energy efficiency aspects. The design guide introduces the principle and key characteristics of room air distribution with diffuse ceiling ventilation and the design...

  9. Protective Ventilation of Preterm Lambs Exposed to Acute Chorioamnionitis Does Not Reduce Ventilation-Induced Lung or Brain Injury

    Science.gov (United States)

    Barton, Samantha K.; Moss, Timothy J. M.; Hooper, Stuart B.; Crossley, Kelly J.; Gill, Andrew W.; Kluckow, Martin; Zahra, Valerie; Wong, Flora Y.; Pichler, Gerhard; Galinsky, Robert; Miller, Suzanne L.

    2014-01-01

    Background The onset of mechanical ventilation is a critical time for the initiation of cerebral white matter (WM) injury in preterm neonates, particularly if they are inadvertently exposed to high tidal volumes (VT) in the delivery room. Protective ventilation strategies at birth reduce ventilation-induced lung and brain inflammation and injury, however its efficacy in a compromised newborn is not known. Chorioamnionitis is a common antecedent of preterm birth, and increases the risk and severity of WM injury. We investigated the effects of high VT ventilation, after chorioamnionitis, on preterm lung and WM inflammation and injury, and whether a protective ventilation strategy could mitigate the response. Methods Pregnant ewes (n = 18) received intra-amniotic lipopolysaccharide (LPS) 2 days before delivery, instrumentation and ventilation at 127±1 days gestation. Lambs were either immediately euthanased and used as unventilated controls (LPSUVC; n = 6), or were ventilated using an injurious high VT strategy (LPSINJ; n = 5) or a protective ventilation strategy (LPSPROT; n = 7) for a total of 90 min. Mean arterial pressure, heart rate and cerebral haemodynamics and oxygenation were measured continuously. Lungs and brains underwent molecular and histological assessment of inflammation and injury. Results LPSINJ lambs had poorer oxygenation than LPSPROT lambs. Ventilation requirements and cardiopulmonary and systemic haemodynamics were not different between ventilation strategies. Compared to unventilated lambs, LPSINJ and LPSPROT lambs had increases in pro-inflammatory cytokine expression within the lungs and brain, and increased astrogliosis (p<0.02) and cell death (p<0.05) in the WM, which were equivalent in magnitude between groups. Conclusions Ventilation after acute chorioamnionitis, irrespective of strategy used, increases haemodynamic instability and lung and cerebral inflammation and injury. Mechanical ventilation is a potential contributor

  10. Protective ventilation of preterm lambs exposed to acute chorioamnionitis does not reduce ventilation-induced lung or brain injury.

    Directory of Open Access Journals (Sweden)

    Samantha K Barton

    Full Text Available The onset of mechanical ventilation is a critical time for the initiation of cerebral white matter (WM injury in preterm neonates, particularly if they are inadvertently exposed to high tidal volumes (VT in the delivery room. Protective ventilation strategies at birth reduce ventilation-induced lung and brain inflammation and injury, however its efficacy in a compromised newborn is not known. Chorioamnionitis is a common antecedent of preterm birth, and increases the risk and severity of WM injury. We investigated the effects of high VT ventilation, after chorioamnionitis, on preterm lung and WM inflammation and injury, and whether a protective ventilation strategy could mitigate the response.Pregnant ewes (n = 18 received intra-amniotic lipopolysaccharide (LPS 2 days before delivery, instrumentation and ventilation at 127±1 days gestation. Lambs were either immediately euthanased and used as unventilated controls (LPSUVC; n = 6, or were ventilated using an injurious high VT strategy (LPSINJ; n = 5 or a protective ventilation strategy (LPSPROT; n = 7 for a total of 90 min. Mean arterial pressure, heart rate and cerebral haemodynamics and oxygenation were measured continuously. Lungs and brains underwent molecular and histological assessment of inflammation and injury.LPSINJ lambs had poorer oxygenation than LPSPROT lambs. Ventilation requirements and cardiopulmonary and systemic haemodynamics were not different between ventilation strategies. Compared to unventilated lambs, LPSINJ and LPSPROT lambs had increases in pro-inflammatory cytokine expression within the lungs and brain, and increased astrogliosis (p<0.02 and cell death (p<0.05 in the WM, which were equivalent in magnitude between groups.Ventilation after acute chorioamnionitis, irrespective of strategy used, increases haemodynamic instability and lung and cerebral inflammation and injury. Mechanical ventilation is a potential contributor to WM injury in infants exposed

  11. Reversible ventilation and perfusion abnormalities in unilateral obstructed lung

    Energy Technology Data Exchange (ETDEWEB)

    Ward, H.E.; Jones, R.L.; King, E.G.; Sproule, B.J.; Fortune, R.L.

    1982-01-01

    An intraluminal carcinoid tumor obstructing the left mainstem bronchus produced hypoxemia through alteration in ventilation/perfusion matching. Studies of regional lung function using 133-xenon (/sup 133/Xe) and a multiprobe computerized instrumentation system documented a reduction of perfusion to 22 percent and ventilation to 6 percent of the total. There was negligible washout of intravenously injected /sup 133/Xe from the left lung consistent with air trapping. Four days after left mainstem bronchial sleeve resection, perfusion, ventilation and washout of injected xenon had significantly improved and by four months postresection, all measurements were virtually normal, although complete restoration of perfusion in relation to ventilation was delayed. Regional lung function studied with a multiprobe system in this patient provided a clinical model for the study of ventilation and perfusion inter-relationships in large airway obstruction and demonstrated that a prolonged time may be required for return of perfusion to normal.

  12. Association Between Noninvasive Ventilation and Mortality Among Older Patients With Pneumonia.

    Science.gov (United States)

    Valley, Thomas S; Walkey, Allan J; Lindenauer, Peter K; Wiener, Renda Soylemez; Cooke, Colin R

    2017-03-01

    Despite increasing use, evidence is mixed as to the appropriate use of noninvasive ventilation in patients with pneumonia. We aimed to determine the relationship between receipt of noninvasive ventilation and outcomes for patients with pneumonia in a real-world setting. We performed a retrospective cohort study of Medicare beneficiaries (aged > 64 yr) admitted to 2,757 acute-care hospitals in the United States with pneumonia, who received mechanical ventilation from 2010 to 2011. Noninvasive ventilation versus invasive mechanical ventilation. The primary outcome was 30-day mortality with Medicare reimbursement as a secondary outcome. To account for unmeasured confounding associated with noninvasive ventilation use, an instrumental variable was used-the differential distance to a high noninvasive ventilation use hospital. All models were adjusted for patient and hospital characteristics to account for measured differences between groups. Among 65,747 Medicare beneficiaries with pneumonia who required mechanical ventilation, 12,480 (19%) received noninvasive ventilation. Patients receiving noninvasive ventilation were more likely to be older, male, white, rural-dwelling, have fewer comorbidities, and were less likely to be acutely ill as measured by organ failures. Results of the instrumental variable analysis suggested that, among marginal patients, receipt of noninvasive ventilation was not significantly associated with differences in 30-day mortality when compared with invasive mechanical ventilation (54% vs 55%; p = 0.92; 95% CI of absolute difference, -13.8 to 12.4) but was associated with significantly lower Medicare spending ($18,433 vs $27,051; p = 0.02). Among Medicare beneficiaries hospitalized with pneumonia who received mechanical ventilation, noninvasive ventilation use was not associated with a real-world mortality benefit. Given the wide CIs, however, substantial harm associated with noninvasive ventilation could not be excluded. The use of noninvasive

  13. What Is a Ventilator?

    Science.gov (United States)

    ... who are on ventilators for shorter periods. The advantage of this tube is that it can be ... Privacy Policy Freedom of Information Act (FOIA) Accessibility Copyright and Usage No FEAR Act Grants and Funding ...

  14. Why We Ventilate

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M.; Sherman, Max H.; Price, Phil N.; Singer, Brett C.

    2011-09-01

    It is widely accepted that ventilation is critical for providing good indoor air quality (IAQ) in homes. However, the definition of"good" IAQ, and the most effective, energy efficient methods for delivering it are still matters of research and debate. This paper presents the results of work done at the Lawrence Berkeley National Lab to identify the air pollutants that drive the need for ventilation as part of a larger effort to develop a health-based ventilation standard. First, we present results of a hazard analysis that identified the pollutants that most commonly reach concentrations in homes that exceed health-based standards or guidelines for chronic or acute exposures. Second, we present results of an impact assessment that identified the air pollutants that cause the most harm to the U.S. population from chronic inhalation in residences. Lastly, we describe the implications of our findings for developing effective ventilation standards.

  15. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per; Nielsen, Peter V.

    2014-01-01

    As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role on...... temperature as well as optimizing the radiant cooling potential by combining with thermal mass is conducted and gives a direction for further investigation....

  16. Conventional mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Tobias Joseph

    2010-01-01

    Full Text Available The provision of mechanical ventilation for the support of infants and children with respiratory failure or insufficiency is one of the most common techniques that are performed in the Pediatric Intensive Care Unit (PICU. Despite its widespread application in the PICUs of the 21st century, before the 1930s, respiratory failure was uniformly fatal due to the lack of equipment and techniques for airway management and ventilatory support. The operating rooms of the 1950s and 1960s provided the arena for the development of the manual skills and the refinement of the equipment needed for airway management, which subsequently led to the more widespread use of endotracheal intubation thereby ushering in the era of positive pressure ventilation. Although there seems to be an ever increasing complexity in the techniques of mechanical ventilation, its successful use in the PICU should be guided by the basic principles of gas exchange and the physiology of respiratory function. With an understanding of these key concepts and the use of basic concepts of mechanical ventilation, this technique can be successfully applied in both the PICU and the operating room. This article reviews the basic physiology of gas exchange, principles of pulmonary physiology, and the concepts of mechanical ventilation to provide an overview of the knowledge required for the provision of conventional mechanical ventilation in various clinical arenas.

  17. Triggering of the ventilator in patient-ventilator interactions.

    Science.gov (United States)

    Sassoon, Catherine Sh

    2011-01-01

    With current ventilator triggering design, in initiating ventilator breaths patient effort is only a small fraction of the total effort expended to overcome the inspiratory load. Similarly, advances in ventilator pressure or flow delivery and inspiratory flow termination improve patient effort or inspiratory muscle work during mechanical ventilation. Yet refinements in ventilator design do not necessarily allow optimal patient-ventilator interactions, as the clinician is key in managing patient factors and selecting appropriate ventilator factors to maintain patient-ventilator synchrony. In patient-ventilator interactions, unmatched patient flow demand by ventilator flow delivery results in flow asynchrony, whereas mismatches between mechanical inspiratory time (mechanical T(I)) and neural T(I) produce timing asynchrony. Wasted efforts are an example of timing asynchrony. In the triggering phase, trigger thresholds that are set too high or the type of triggering methods induces wasted efforts. Wasted efforts can be aggravated by respiratory muscle weakness or other conditions that reduce respiratory drive. In the post-triggering phase, ventilator factors play an important role in patient-ventilator interaction; this role includes the assistance level, set inspiratory flow rate, T(I), pressurization rate, and cycling-off threshold, and to some extent, applied PEEP. This paper proposes an algorithm that clinicians can use to adjust ventilator settings with the goal to eliminate or reduce patients' wasted efforts.

  18. Mechanical ventilation strategies.

    Science.gov (United States)

    Keszler, Martin

    2017-08-01

    Although only a small proportion of full term and late preterm infants require invasive respiratory support, they are not immune from ventilator-associated lung injury. The process of lung damage from mechanical ventilation is multifactorial and cannot be linked to any single variable. Atelectrauma and volutrauma have been identified as the most important and potentially preventable elements of lung injury. Respiratory support strategies for full term and late preterm infants have not been as thoroughly studied as those for preterm infants; consequently, a strong evidence base on which to make recommendations is lacking. The choice of modalities of support and ventilation strategies should be guided by the specific underlying pathophysiologic considerations and the ventilatory approach must be individualized for each patient based on the predominant pathophysiology at the time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. CFD and Ventilation Research

    DEFF Research Database (Denmark)

    Li, Y.; Nielsen, Peter V.

    2011-01-01

    There has been a rapid growth of scientific literature on the application of computational fluid dynamics (CFD) in the research of ventilation and indoor air science. With a 1000–10,000 times increase in computer hardware capability in the past 20 years, CFD has become an integral part...... of scientific research and engineering development of complex air distribution and ventilation systems in buildings. This review discusses the major and specific challenges of CFD in terms of turbulence modelling, numerical approximation, and boundary conditions relevant to building ventilation. We emphasize...... the growing need for CFD verification and validation, suggest on-going needs for analytical and experimental methods to support the numerical solutions, and discuss the growing capacity of CFD in opening up new research areas. We suggest that CFD has not become a replacement for experiment and theoretical...

  20. Ventilation with heat recovery

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2005-01-01

    This paper presents the experiences from the use of ventilation with heat recovery in several experimental single-family houses developed and built within the last four years to meet the new Danish energy requirements of 2005. Included are descriptions of the ventilation system components...... and the main functional demands as well as measurements of the thermal efficiency, electricity consumptions and building air tightness. The paper addresses the aspects of minimizing the heat loss from the duct system and the heat recovery unit (when placed in an unheated attic space) in order to obtain...

  1. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.; Walker, Iain S.

    2011-04-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).

  2. Hybrid Ventilation Air Flow Process

    DEFF Research Database (Denmark)

    Heiselberg, Per Kvols

    The scope of this annex is therefore to obtain better knowledge of the use of hybrid ventilation technologies. The annex focus on development of control strategies for hybrid ventilation, on development of methods to predict hybrid ventilation performance in office buildings and on implementation...

  3. Ventilation Criteria for Aeromedical Evacuation.

    Science.gov (United States)

    1986-09-01

    number) FIELD GROUP i SUB-GROUP Aeromedical evacuation; Ventilatory requirements; 06 11 06 12 iAir evacuation; and Mechanical ventilation . 19...ABSTRACT (Continue on reverse if necessary and identify by block number) -., fr evacLation of patients requiring mechanical ventilation exposes these...reasonably stable from a medical standpoint; none required mechanical ventilation . Unfortunately, we find no .- , studies that describe the

  4. The amazing Minivent ventilator

    African Journals Online (AJOL)

    TYYCVNCi2nM. Acknowledgements – The authors wish to thank Dr Christine Ball for the photograph of Dr Cohen and Dr Cohen for providing them with the last Minivent ventilator in his possession. It is still functioning and may be seen in the Nagin ...

  5. Measure Guideline: Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Springer, D.; Dakin, B.; German, A.

    2012-04-01

    The purpose of this measure guideline on ventilation cooling is to provide information on a cost-effective solution for reducing cooling system energy and demand in homes located in hot-dry and cold-dry climates. This guideline provides a prescriptive approach that outlines qualification criteria, selection considerations, and design and installation procedures.

  6. Understanding mechanical ventilators.

    Science.gov (United States)

    Chatburn, Robert L

    2010-12-01

    The respiratory care academic community has not yet adopted a standardized system for classifying and describing modes of ventilation. As a result, there is enough confusion that patient care, clinician education and even ventilator sales are all put at risk. This article summarizes a ventilator mode taxonomy that has been extensively published over the last 15 years. Specifically, the classification system has three components: a description of the control variables within breath; a description of the sequence of mandatory and spontaneous breaths; and a specification for the targeting scheme. This three-level specification provides scalability of detail to make the mode description appropriate for the particular need. At the bedside, we need only refer to a mode briefly using the first or perhaps first and second components. To distinguish between similar modes and brand names, we would need to include all components. This taxonomy uses the equation of motion for the respiratory system as the underlying theoretical framework. All terms relevant to describing modes of mechanical ventilation are defined in an extensive appendix.

  7. Mechanical ventilation of mice

    NARCIS (Netherlands)

    Schwarte, L. A.; Zuurbier, C. J.; Ince, C.

    2000-01-01

    Due to growing interest in murine functional genomics research, there is an increasing need for physiological stable in vivo murine models. Of special importance is support and control of ventilation by artificial respiration, which is difficult to execute as a consequence of the small size of the

  8. Ventilation for Free

    NARCIS (Netherlands)

    Scholten, R.D.; Ter Haar, J.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0533 Innovation & Sustainability. The goal of this manual is to give a clear and simple overview of some of the possibilities for using natural ventilation in buildings. These systems are described through their formulas to give an idea of

  9. Elforbrug til mekanisk ventilation

    DEFF Research Database (Denmark)

    Olufsen, P.

    I Energi 2000 er ventilationsområdet udpeget som et af de områder, hvor der bør tages initiativ til at fremme elbesparelser. I rapporten beskrives og analyseres målinger af elforbruget til ventilation i 12 bygninger, der alle anvendes til administration eller lignende formål. På grundlag af...

  10. Patient-ventilator dyssynchrony during assisted invasive mechanical ventilation.

    Science.gov (United States)

    Murias, G; Villagra, A; Blanch, L

    2013-04-01

    Patient-ventilator dyssynchrony is common during mechanical ventilation. Dyssynchrony decreases comfort, prolongs mechanical ventilation and intensive care unit stays, and might lead to worse outcome. Dyssynchrony can occur during the triggering of the ventilator, the inspiration period after triggering, the transition from inspiration to expiration, and the expiratory phase. The most common dyssynchronies are delayed triggering, autotriggering, ineffective inspiratory efforts (which can occur at any point in the respiratory cycle), mismatch between the patient's and ventilator's inspiratory times, and double triggering. At present, the detection of dyssynchronies usually depends on healthcare staff observing ventilator waveforms; however, performance is suboptimal and many events go undetected. To date, technological complexity has made it impossible to evaluate patient-ventilator synchrony throughout the course of mechanical ventilation. Studies have shown that a high index of dyssynchrony may increase the duration of mechanical ventilation. Better training, better ventilatory modes, and/or computerized systems that permit better synchronization of patients' demands and ventilator outputs are necessary to improve patient-ventilator synchrony.

  11. Performance of ductless personalized ventilation in conjunction with displacement ventilation

    DEFF Research Database (Denmark)

    Dalewski, Mariusz; Melikov, Arsen Krikor; Vesely, Michal

    2014-01-01

    The performance of ductless personalized ventilation (DPV) in conjunction with displacement ventilation was studied and compared with displacement ventilation alone and mixing ventilation. Thirty subjects were exposed in a climate chamber to environmental conditions representing three levels...... perception of the environment. The subjects could control the position of the DPV supply diffuser and the personalized air flow (air velocity). The use of DPV improved perceived air quality and thermal comfort compared to displacement ventilation alone. At 26 °C and 29 °C the percentage dissatisfied with air...... movement decreased with DPV compared to corresponding conditions with displacement ventilation alone and reached the same level as mixing or displacement ventilation at 23 °C. Subjects were able to control the volume and speed of the personalized air flow in order to avoid eye irritation. However...

  12. Human response to ductless personalized ventilation coupled with displacement ventilation

    DEFF Research Database (Denmark)

    Dalewski, Mariusz; Veselý, Michal; Melikov, Arsen K.

    2012-01-01

    A human subject experiment was carried out to investigate the extent to which ductless personalized ventilation (DPV) in conjunction with displacement ventilation can improve perceived air quality (PAQ) and thermal comfort at elevated room air temperature in comparison with displacement ventilation...... alone. The experimental conditions comprised displacement ventilation alone (room air temperature of 23 °C, 26 °C, 29 °C) and DPV with displacement ventilation (26 °C, 29 °C), both operating at supply air temperatures 3, 5 or 6K lower than room air temperature, as well as mixing ventilation (23 °C, 3 K......). During one hour exposure participants answered questionnaires regarding PAQ and thermal comfort. PAQ was significantly better with DPV than without DPV at the same background conditions. Thermal comfort improved when DPV was used. Combining DPV with displacement ventilation showed the potential...

  13. Design Procedure for Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Tjelflaat, Per Olaf

    Mechanical and natural ventilation systems have developed separately during many years. The natural next step in this development is development of ventilation concepts that utilises and combines the best features from each system into a new type of ventilation system - Hybrid Ventilation....... Buildings with hybrid ventilation often include other sustainable technologies and an energy optimisation requires an integrated approach in the design of the building and its mechanical systems. Therefore, the hybrid ventilation design procedure differs from the design procedure for conventional HVAC....... The first ideas on a design procedure for hybrid ventilation is presented and the different types of design methods, that is needed in different phases of the design process, is discussed....

  14. ASHRAE and residential ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H.

    2003-10-01

    In the last quarter of a century, the western world has become increasingly aware of environmental threats to health and safety. During this period, people psychologically retreated away from outdoors hazards such as pesticides, smog, lead, oil spills, and dioxin to the seeming security of their homes. However, the indoor environment may not be healthier than the outdoor environment, as has become more apparent over the past few years with issues such as mold, formaldehyde, and sick-building syndrome. While the built human environment has changed substantially over the past 10,000 years, human biology has not; poor indoor air quality creates health risks and can be uncomfortable. The human race has found, over time, that it is essential to manage the indoor environments of their homes. ASHRAE has long been in the business of ventilation, but most of the focus of that effort has been in the area of commercial and institutional buildings. Residential ventilation was traditionally not a major concern because it was felt that, between operable windows and envelope leakage, people were getting enough outside air in their homes. In the quarter of a century since the first oil shock, houses have gotten much more energy efficient. At the same time, the kinds of materials and functions in houses changed in character in response to people's needs. People became more environmentally conscious and aware not only about the resources they were consuming but about the environment in which they lived. All of these factors contributed to an increasing level of public concern about residential indoor air quality and ventilation. Where once there was an easy feeling about the residential indoor environment, there is now a desire to define levels of acceptability and performance. Many institutions--both public and private--have interests in Indoor Air Quality (IAQ), but ASHRAE, as the professional society that has had ventilation as part of its mission for over 100 years, is the

  15. [Ventilation-perfusion ratios].

    Science.gov (United States)

    Schaffartzik, W

    1994-10-01

    Knowledge of normal and impaired pulmonary gas exchange is essential to the anaesthesiologist. Analysis of an arterial blood sample allows evaluation of whether or not pulmonary gas exchange is normal. For this purpose comparison with the oxygenation index or the alveolar-arterial PO2 difference is helpful. Pathological changes of these variables are mainly caused by ventilation-perfusion (VA/Q) mismatch. In daily practice, venous admixture or intrapulmonary shunt can be calculated using arterial and mixed-venous blood. By analysing arterial and expired PCO2, dead-space ventilation can be determined, but extended analyses of VA/Q distribution are not possible in daily practice. However, knowledge of the principles of typical disturbances of pulmonary gas exchange in acute and chronic lung disease allows the use of therapeutic strategies based on the pathophysiological changes.

  16. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    -cooling period and night cooling potential. The investment cost of this ventilation system is about 5-10% lower than the conventional ones, because the acoustic ceiling could be directly applied as air diffuser and the use of plenum to distribute air reduces the cost of ductwork. There is a growing interest...... and manufacturers and the users of diffuse ceiling technology. The design guide introduces the principle and key characteristics of room air distribution with diffuse ceiling ventilation. It provides an overview of potential benefit and limitations of this technology. The benefits include high thermal comfort, high...... cooling capacity, energy saving, low investment cost and low noise level; while the limitations include condensation risk and the limit on the room geometry. Furthermore, the crucial design parameters are summarized and their effects on the system performance are discussed. In addition to the stand...

  17. Ventilation i industrien

    DEFF Research Database (Denmark)

    Valbjørn, O.

    I en række afsnit belyses problemer med træk, kulde, varme, og luftforurening på industriens arbejdspladser, og hvordan man ved ventilation og bygningsudformning kan bekæmpe disse gener. Hvert afsnit kan i princippet læses for sig, og anvisningen kan derfor bruges som håndbog, både af de der er...

  18. Noninvasive mechanical ventilation

    OpenAIRE

    Karakurt, Sait

    2016-01-01

    Noninvasive mechanical ventilation (NIMV) has been widelyapplied to the patient with respiratory failure since 1990’s aroundthe world. The respiratory function of the patient with respiratoryfailure should be supported by using positive pressure ventilationuntil primary problem of the patient is treated. Positive pressureshould be given noninvasively or invasively. If the patient isconscious (except unconsiousness due to CO2 retention) and hasintact bulber function(sufficient cough reflex and...

  19. SEPARATION OF MECHANICAL VENTILATION

    OpenAIRE

    Ida Bagus Wisnu Parbawa Kusuma; I Nengah Kuning Atmajaya

    2014-01-01

    The weaning from mechanical ventilation can be defined as the process of letting theventilator either directly or in stages. Indication of weaning from mechanicalventilation, seen from several parameters such as disease processes, PaO2, PEEP,FiO2, pH, Hb, awareness, body temperature, cardiac function, lung function, drugssedative agent or paralysis agent, and psicologic status of patient. Based on thelength of the weaning, can be devided into two, long-term weaning dan short-termweaning. Shor...

  20. Ventilation i industrien

    DEFF Research Database (Denmark)

    Valbjørn, O.

    I en række afsnit belyses problemer med træk, kulde, varme, og luftforurening på industriens arbejdspladser, og hvordan man ved ventilation og bygningsudformning kan bekæmpe disse gener. Hvert afsnit kan i princippet læses for sig, og anvisningen kan derfor bruges som håndbog, både af de der er u...

  1. Harnessing natural ventilation benefits.

    Science.gov (United States)

    O'Leary, John

    2013-04-01

    Making sure that a healthcare establishment has a good supply of clean fresh air is an important factor in keeping patients, staff, and visitors, free from the negative effects of CO2 and other contaminants. John O'Leary of Trend Controls, a major international supplier of building energy management solutions (BEMS), examines the growing use of natural ventilation, and the health, energy-saving, and financial benefits, that it offers.

  2. Purge ventilation operability

    Energy Technology Data Exchange (ETDEWEB)

    Marella, J.R.

    1995-04-10

    A determination of minimum requirements for purge exhaust ventilation system operability has been performed. HLWE and HLW Regulatory Program personnel have evaluated the various scenarios of equipment conditions and HLWE has developed the requirements for purge exhaust systems. This report is provided to document operability requirements to assist Tank Farm personnel to determine whether a system is operable/inoperable and to define required compensatory actions.

  3. Mine ventilation. I. Wentylacja kopaln. I

    Energy Technology Data Exchange (ETDEWEB)

    Nedza, Z.; Rosiek, F.

    1975-01-01

    Methods of determining the following components of mine air are characterized: oxygen, nitrogen, carbon monoxide, carbon dioxide, nitrogen oxides, hydrogen sulphide, sulphur dioxide, methane, hydrogen and water vapour. Practical advice is also given on determining the composition of mine air citing relevant Polish standards concerning work safety in mines, including coal mines. Principles of work and technical specification of the individual measuring instruments are provided. Advantages and disadvantages of using various apparatus are critically evaluated. Additional problems of mine ventilation such as dustiness of mine air and combatting dustiness of mine air are also discussed. (25 refs.)

  4. Pretest Predictions for Ventilation Tests

    Energy Technology Data Exchange (ETDEWEB)

    Y. Sun; H. Yang; H.N. Kalia

    2007-01-17

    The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, concrete pipe walls, and insulation that will be developed during the ventilation tests involving various test conditions. The results will be used as input to the following three areas: (1) Decisions regarding testing set-up and performance. (2) Assessing how best to scale the test phenomena measured. (3) Validating numerical approach for modeling continuous ventilation. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the ventilation tests, and develop and describe numerical methods that can be used to calculate the effects of continuous ventilation. Sensitivity studies to assess the impact of variation of linear power densities (linear heat loads) and ventilation air flow rates are included. The calculation is limited to thermal effect only.

  5. Performance of Portable Ventilators Following Storage at Temperature Extremes.

    Science.gov (United States)

    Blakeman, Thomas C; Rodriquez, Dario; Britton, Tyler J; Johannigman, Jay A; Petro, Michael C; Branson, Richard D

    2016-05-01

    In the current theater of operation, medical devices are often shipped and stored at ambient conditions. The effect of storage at hot and cold temperature extremes on ventilator performance is unknown. We evaluated three portable ventilators currently in use or being evaluated for use by the Department of Defense (731, Impact Instrumentation; T1, Hamilton Medical; and Revel, CareFusion) at temperature extremes in a laboratory setting. The ventilators were stored at temperatures of 60°C and -35°C for 24 hours and were allowed to acclimate to room temperature for 30 minutes before evaluation. The T1 required an extra 15 to 30 minutes of acclimation to room temperature before the ventilator would deliver breaths. All delivered tidal volumes at room temperature and after storage at temperature extremes were less than the ±10% American Society for Testing and Materials standard with the Revel. Delivered tidal volumes at the pediatric settings were less than the ±10% threshold after storage at both temperatures and at room temperature with the 731. Storage at extreme temperature affected the performance of the portable ventilators tested. This study showed that portable ventilators may need an hour or more of acclimation time at room temperature after storage at temperature extremes to operate as intended. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

  6. Mechanical ventilation in neurosurgical patients

    OpenAIRE

    Keshav Goyal; Ranadhir Mitra; Shweta Kedia

    2013-01-01

    Mechanical ventilation significantly affects cerebral oxygenation and cerebral blood flow through changes in arterial carbon dioxide levels. Neurosurgical patients might require mechanical ventilation for correction and maintenance of changes in the pulmonary system that occur either due to neurosurgical pathology or following surgery during the acute phase. This review discusses the basics of mechanical ventilation relevant to the neurosurgeon in the day-to-day management of neurosurgical pa...

  7. Mechanical ventilation in neurosurgical patients

    Directory of Open Access Journals (Sweden)

    Keshav Goyal

    2013-01-01

    Full Text Available Mechanical ventilation significantly affects cerebral oxygenation and cerebral blood flow through changes in arterial carbon dioxide levels. Neurosurgical patients might require mechanical ventilation for correction and maintenance of changes in the pulmonary system that occur either due to neurosurgical pathology or following surgery during the acute phase. This review discusses the basics of mechanical ventilation relevant to the neurosurgeon in the day-to-day management of neurosurgical patient requiring artificial support of the respiration.

  8. Ventilation Surge Techniques. Volume I

    Science.gov (United States)

    1981-12-01

    Whon Data Rntere), 20. The experimental program examined airflow patterns for both mechanically driven and thermally driven ventilation . Mechanical ...were used in the study. *The experimental program examined airflow patterns for both mechanically driven and thermally driven ventilation . Mechanical ... Ventilation can be supplied by mechanical means such as fans, blowers, and pumps or by natural forces such’as those created by wind or thermal buoyancy. The

  9. Design Principles for Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system- Hybrid Ventilation. ....... The hybrid ventilation concepts, design challenges and principles are discussed and illustrated by four building examples....

  10. Design Principles for Natural and Hybrid Ventilation

    OpenAIRE

    Heiselberg, Per

    2000-01-01

    For many years mechanical and natural ventilation systems have developed separately. Naturally, the next step in this development is the development of ventilation concepts that utilize and combine the best features from each system to create a new type of ventilation system- Hybrid Ventilation. The hybrid ventilation concepts, design challenges and principles are discussed and illustrated by four building examples.

  11. Long-Term Mechanical Ventilation.

    Science.gov (United States)

    Sahetya, Sarina; Allgood, Sarah; Gay, Peter C; Lechtzin, Noah

    2016-12-01

    Although precise numbers are difficult to obtain, the population of patients receiving long-term ventilation has increased over the last 20 years, and includes patients with chronic lung diseases, neuromuscular diseases, spinal cord injury, and children with complex disorders. This article reviews the equipment and logistics involved with ventilation outside of the hospital. Discussed are common locations for long-term ventilation, airway and secretion management, and many of the potential challenges faced by individuals on long-term ventilation. Published by Elsevier Inc.

  12. Liberation from prolonged mechanical ventilation.

    Science.gov (United States)

    Scheinhorn, David J; Chao, David C; Stearn-Hassenpflug, Meg

    2002-07-01

    days in the acute care hospital before referral, 74 days in the LTAC afterward), and a 67% mortality in postdischarge follow-up to day 180. Results of functional status studies and quality-of-life (QQL) measures, some using validated instruments, are now being reported in small series of PMV patients. These will merit consideration as important as weaning outcome, disposition, and survival data, as they accumulate to round out the treatment results in this population. Using a proprietary instrument, Carson et al [9] found 42% of 1-year survivors, that is, 8% of study patients, functionally independent at 1 year after discharge. Nasraway [25], using a single-question QQL assessment, and a validated functionality measurement, found 11.5% of his original cohort at home, breathing independently, with a "fair or better" QOL and good physical functionality. In a preliminary report from Dr. Criner's VRU, objective physical improvement was demonstrated in rehabilitation after PMV, using a functional independence measure scale [89]. A full report from the same unit, using a Sickness Impact Profile score makes it clear that PMV had no independent adverse effect on QOL several years later [135]. The 46 patients (25 of whom, with mean age 59 years, responded to the follow-up questionnaire), followed for 24 months after the catastrophic episode, scored their QOL based on their underlying chronic diseases, if any. The older patients, status postsurgical illness, predominantly cardiac surgery, rated their QOL better than younger patients with acute or chronic diseases. Similar findings have been reported in a recent ICU study, reporting QOL after prolonged intensive care [136]. Those who work to liberate PMV patients from mechanical ventilation, a satisfying end in many ways, have demonstrated that this post-ICU critical care activity is usually safe, and successful, although only in observational studies. Will multicenter studies in PMV patients liberated from mechanical ventilation

  13. Monitoring during Mechnical Ventilation

    Directory of Open Access Journals (Sweden)

    Dean Hess

    1996-01-01

    Full Text Available Monitoring is a continuous, or nearly continuous, evaluation of the physiological function of a patient in real time to guide management decisions, including when to make therapeutic interventions and assessment of those interventions. Pulse oximeters pass two wavelengths of light through a pulsating vascular bed and determine oxygen saturation. The accuracy of pulse oximetry is about ±4%. Capnography measures carbon dioxide at the airway and displays a waveform called the capnogram. End-tidal PCO2 represents alveolar PCO2 and is determined by the ventilation-perfusion quotient. Use of end-tidal PCO2 as an indication of arterial PCO2 is often deceiving and incorrect in critically ill patients. Because there is normally very little carbon dioxide in the stomach, a useful application of capnography is the detection of esophageal intubation. Intra-arterial blood gas systems are available, but the clinical impact and cost effectiveness of these is unclear. Mixed venous oxygenation (PvO2 or SvO2 is a global indicator of tissue oxygenation and is affected by arterial oxygen content, oxygen consumption and cardiac output. Indirect calorimetry is the calculation of energy expenditure and respiratory quotient by the measurement of oxygen consumption and carbon dioxide production. A variety of mechanics can be determined in mechanically ventilated patients including resistance, compliance, auto-peak end-expiratory pressure (PEEP and work of breathing. The static pressure-volume curve can be used to identify lower and upper infection points, which can be used to determine the appropriate PEEP setting and to avoid alveolar overdistension. Although some forms of monitoring have become a standard of care during mechanical ventilation (eg, pulse oximetry, there is little evidence that use of any monitor affects patient outcome.

  14. Plane Stratified Flow in a Room Ventilated by Displacement Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Nickel, J.; Baron, D. J. G.

    2004-01-01

    The air movement in the occupied zone of a room ventilated by displacement ventilation exists as a stratified flow along the floor. This flow can be radial or plane according to the number of wall-mounted diffusers and the room geometry. The paper addresses the situations where plane flow...

  15. Monitoring ventilation during anesthesia.

    Science.gov (United States)

    Kay, B

    1978-01-01

    In patients under anesthesia, ventilation is often monitored less adequately than circulation. A simple method, neglected in adults, is the use of a precordial or oesophageal stethoscope. Respiratory volumes may be measured directly, or inferred from flowrates or pressure changes. A rough measurement of inspired volumes may be made using a nonrebreathing valve, and controlling fresh gas input to maintain a constant underfilled reservoir bag. Spirometry of expired volumes is difficult and requires sophisticated apparatus. Respiratory volumes are easily inferred from flowrates using the Wright or Dräger respirometers. Flowrates may also be inferred from pressure changes, which are easy to record, as in the pneumotachorgraph. Accurate measurements require attention to many details, such as linearity of the transducer response over the flowrates measured. Calibration should be with the anesthetic gases used, at controlled temperature and humidity. Positive pressure ventilation peaks give a high flow artefact, and electronic drift requires regular recalibration. Electrical impedance changes may also be used to infer and record respiratory volumes, with reasonable accuracy if individual calibration is carried out. Anesthesia offers excellent opportunities to measure compliance and resistance, but itself changes these values, so that relation to normal values or changes due to pathology is difficult. Occlusion pressure is also readily measured during anesthesia, as an indication of respiratory drive, but rigid control of all other factors affecting respiratory muscle tensions is necessary.

  16. Thermal plumes in ventilated rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    1990-01-01

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects. Free...... to be the only possible approach to obtain the volume flow in: thermal plumes in ventilated rooms....

  17. Lecture Notes on Mixing Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    The main task of the ventilation system or the air-conditioning system is to supply· and remove air and airborne materials and to supply or remove heat from a room. The necessary level of fresh air will be supplied to· a room by a ventilation system, and heat from equipment or solar radiation can...

  18. Ventilation and Heat Recovering System

    Directory of Open Access Journals (Sweden)

    Olga Bancea

    2007-01-01

    Full Text Available Some aspects concerning the heat reducing for ventilation, achieved by using heat recovering components and a combined heating--ventilating system, assuring both comfort and human health are presented. The floor imbedded systems together with air outlets elements could fulfill all the aesthetically desires, as well as comfort and they are ideal for family houses.

  19. Innovation in home mechanical ventilation

    NARCIS (Netherlands)

    Hazenberg, Andrea

    2017-01-01

    Patients on home mechanical ventilation (HMV) are ventilator dependent, usually for the rest of their lives. In the past decades, the number of patients on HMV increased to nearly 3,000 in 2016 in the Netherlands. Current indications for HMV are patients diagnosed with either neuromuscular disease,

  20. Free Convection Personalized Ventilation (FCPV)

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Normally we supply fresh air to a room with a diffuser, and this air is distributed in the room according to different principles as: mixing ventilation, displacement ventilation etc. That means we have to supply a very large amount of air to the whole room, although a person in the room totally ...

  1. Radioisotope instruments

    CERN Document Server

    Cameron, J F; Silverleaf, D J

    1971-01-01

    International Series of Monographs in Nuclear Energy, Volume 107: Radioisotope Instruments, Part 1 focuses on the design and applications of instruments based on the radiation released by radioactive substances. The book first offers information on the physical basis of radioisotope instruments; technical and economic advantages of radioisotope instruments; and radiation hazard. The manuscript then discusses commercial radioisotope instruments, including radiation sources and detectors, computing and control units, and measuring heads. The text describes the applications of radioisotop

  2. Natural ventilation for free stall dairy barns

    OpenAIRE

    Gay, Susan Wood

    2009-01-01

    Natural ventilation is a result of a combination good construction, correct temperature, humidity control, air exchange. This publication discusses how to achieve natural ventilation in your structure.

  3. Inhalation therapy in mechanical ventilation

    Science.gov (United States)

    Maccari, Juçara Gasparetto; Teixeira, Cassiano; Gazzana, Marcelo Basso; Savi, Augusto; Dexheimer-Neto, Felippe Leopoldo; Knorst, Marli Maria

    2015-01-01

    Patients with obstructive lung disease often require ventilatory support via invasive or noninvasive mechanical ventilation, depending on the severity of the exacerbation. The use of inhaled bronchodilators can significantly reduce airway resistance, contributing to the improvement of respiratory mechanics and patient-ventilator synchrony. Although various studies have been published on this topic, little is known about the effectiveness of the bronchodilators routinely prescribed for patients on mechanical ventilation or about the deposition of those drugs throughout the lungs. The inhaled bronchodilators most commonly used in ICUs are beta adrenergic agonists and anticholinergics. Various factors might influence the effect of bronchodilators, including ventilation mode, position of the spacer in the circuit, tube size, formulation, drug dose, severity of the disease, and patient-ventilator synchrony. Knowledge of the pharmacological properties of bronchodilators and the appropriate techniques for their administration is fundamental to optimizing the treatment of these patients. PMID:26578139

  4. Inhalation therapy in mechanical ventilation.

    Science.gov (United States)

    Maccari, Juçara Gasparetto; Teixeira, Cassiano; Gazzana, Marcelo Basso; Savi, Augusto; Dexheimer-Neto, Felippe Leopoldo; Knorst, Marli Maria

    2015-01-01

    Patients with obstructive lung disease often require ventilatory support via invasive or noninvasive mechanical ventilation, depending on the severity of the exacerbation. The use of inhaled bronchodilators can significantly reduce airway resistance, contributing to the improvement of respiratory mechanics and patient-ventilator synchrony. Although various studies have been published on this topic, little is known about the effectiveness of the bronchodilators routinely prescribed for patients on mechanical ventilation or about the deposition of those drugs throughout the lungs. The inhaled bronchodilators most commonly used in ICUs are beta adrenergic agonists and anticholinergics. Various factors might influence the effect of bronchodilators, including ventilation mode, position of the spacer in the circuit, tube size, formulation, drug dose, severity of the disease, and patient-ventilator synchrony. Knowledge of the pharmacological properties of bronchodilators and the appropriate techniques for their administration is fundamental to optimizing the treatment of these patients.

  5. Computational Fluid Dynamics in Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Allard, Francis; Awbi, Hazim B.

    2008-01-01

    Computational Fluid Dynamics in Ventilation Design is a new title in the is a new title in the REHVA guidebook series. The guidebook is written for people who need to use and discuss results based on CFD predictions, and it gives insight into the subject for those who are not used to work with CFD....... The guidebook is also written for people working with CFD which have to be more aware of how this numerical method is applied in the area of ventilation. The guidebook has, for example, chapters that are very important for CFD quality control in general and for the quality control of ventilation related...

  6. Pulmonary mechanics during mechanical ventilation.

    Science.gov (United States)

    Henderson, William R; Sheel, A William

    2012-03-15

    The use of mechanical ventilation has become widespread in the management of hypoxic respiratory failure. Investigations of pulmonary mechanics in this clinical scenario have demonstrated that there are significant differences in compliance, resistance and gas flow when compared with normal subjects. This paper will review the mechanisms by which pulmonary mechanics are assessed in mechanically ventilated patients and will review how the data can be used for investigative research purposes as well as to inform rational ventilator management. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Contaminant Distribution Around Persons in Rooms Ventilated by Displacement Ventilation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter V.

    An optimal design of the ventilation system needs a proper prediction of the velocity, temperature and contaminant distribution in the room. Traditionally this is done either by the use of simplified models or by a somewhat more comprehensive CFD-simulation. Common to both methods is usually the ...... the lack of consideration for the persons present in the room. This paper deals with some of the effects of persons present in a displacement ventilated room, especially the effect on the contaminant distribution....

  8. An overview of the TA-55, Building PF-4 ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-02-22

    An overview of the TA-55, Building PF-4 ventilation system is provided in the following sections. Included are descriptions of the zone configurations, equipment-performance criteria, ventilation support systems, and the ventilation-system evaluation criteria. Section 4.2.1.1 provides a brief discussion of the ventilation system function. Section 4.2.1.2 provides details on the overall system configuration. Details of system interfaces and support systems are provided in Section 4.2.1.3. Section 4.2.1.4 describes instrumentation and control needed to operate the ventilation system. Finally, Sections 4.2.1.5 and 4.2.1.6 describe system surveillance/maintenance and Technical Safety Requirements (TSR) Limitations, respectively. Note that the numerical parameters included in this description are considered nominal; set points and other specifications actually fall within operational bands.

  9. Preoperational test report, vent building ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  10. Performance of Portable Ventilators at Altitude

    Science.gov (United States)

    2015-03-30

    of equipment at altitude. Changes in barometric pressure can affect the performance of mechanical ventilators calibrated for operation at sea level...performance of mechanical ventilators calibrated for operation at sea level. Deploying ventilators that can maintain a consistent tidal volume (VT) delivery...temperature, density, and humidity. These changes can affect the performance of mechanical ventilators calibrated for operation at sea level. The

  11. Climate control of natural ventilated pig houses

    NARCIS (Netherlands)

    Bontsema, J.; Straten, van G.; Salomons, L.; Klooster, van 't C.E.

    1996-01-01

    Ventilation in pig houses is important for maintaining a good climate for the welfare of animals and humans and for an optimal production. Mechanical ventilation has a good performance, since the ventilation rate can easily be controlled, but it is energy demanding, whereas natural ventilation is

  12. Use of Adaptive Support Ventilation (ASV in Ventilator Associated Pneumonia (VAP - A Case Report

    Directory of Open Access Journals (Sweden)

    Bipphy Kath

    2009-01-01

    Full Text Available Prolonged ventilation leads to a higher incidence of ventilator associated pneumonia(VAP resulting in ventilator dependency, increased costs and subsequent weaning failures. Prevention and aggressive treatment of VAP alongwith patient friendly newer modes of ventilation like adaptive support ventilation go a long way in successful management of these cases.

  13. Equivalence in Ventilation and Indoor Air Quality

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  14. Mechanical ventilation in obese patients

    National Research Council Canada - National Science Library

    Leme Silva, P; Pelosi, P; Rocco, P R M

    2012-01-01

    Recent data show an alarming increasing trend in obesity around the world. Mechanical ventilation in this population requires specific ventilatory settings due to the mechanical and inflammatory alterations observed in obesity...

  15. Low-energy mechanical ventilation

    DEFF Research Database (Denmark)

    Andersen, Claus Wessel; Hviid, Christian Anker

    2014-01-01

    and with as little energy consumption as 41.1 kWh/m2/year including heating and all building services with no use of renewable energy such as PVcells or solar heating. One of the key means of reaching the objectives was to implement mechanical ventilation with low pressure loss and therefore low energy consumption....... The project consists of two buildings, building one is 6 stories high, and building two is 4 stories high. The buildings have a gross area of 50,500 m2 including underground parking. The ventilation and indoor climate concept was to use mechanical ventilation together with mechanical cooling and fanassisted......, with an average of 1.1 kJ/m3. The yearly mean SFP based on estimated runtime is approx. 0.8 kJ/m3. The case shows the unlocked potential that lies within mechanical ventilation for nearzero energy consuming buildings....

  16. Innovation in home mechanical ventilation

    OpenAIRE

    Hazenberg, Andrea

    2017-01-01

    Patients on home mechanical ventilation (HMV) are ventilator dependent, usually for the rest of their lives. In the past decades, the number of patients on HMV increased to nearly 3,000 in 2016 in the Netherlands. Current indications for HMV are patients diagnosed with either neuromuscular disease, spine deformities, lung disease or sleep apnea. Improving the quality of life by reducing the complaints of chronic respiratory failure is the ultimate goal for HMV. In the Netherlands patients hav...

  17. Wind Extraction for Natural Ventilation

    Science.gov (United States)

    Fagundes, Tadeu; Yaghoobian, Neda; Kumar, Rajan; Ordonez, Juan

    2017-11-01

    Due to the depletion of energy resources and the environmental impact of pollution and unsustainable energy resources, energy consumption has become one of the main concerns in our rapidly growing world. Natural ventilation, a traditional method to remove anthropogenic and solar heat gains, proved to be a cost-effective, alternative method to mechanical ventilation. However, while natural ventilation is simple in theory, its detailed design can be a challenge, particularly for wind-driven ventilation, which its performance highly involves the buildings' form, surrounding topography, turbulent flow characteristics, and climate. One of the main challenges with wind-driven natural ventilation schemes is due to the turbulent and unpredictable nature of the wind around the building that impose complex pressure loads on the structure. In practice, these challenges have resulted in founding the natural ventilation mainly on buoyancy (rather than the wind), as the primary force. This study is the initial step for investigating the physical principals of wind extraction over building walls and investigating strategies to reduce the dependence of the wind extraction on the incoming flow characteristics and the target building form.

  18. Mechanical ventilation after lung transplantation.

    Science.gov (United States)

    Thakuria, Louit; Davey, Rosada; Romano, Rosalba; Carby, Martin R; Kaul, Sundeep; Griffiths, Mark J; Simon, André R; Reed, Anna K; Marczin, Nandor

    2016-02-01

    To explore the hypothesis that early ventilation strategies influence clinical outcomes in lung transplantation, we have examined our routine ventilation practices in terms of tidal volumes (Vt) and inflation pressures. A total of 124 bilateral lung transplants between 2010 and 2013 were retrospectively assigned to low (8 mL/kg) Vt groups based on ventilation characteristics during the first 6 hours after surgery. Those same 124 patients were also stratified to low-pressure (<25 cm H2O) and high-pressure (≥25 cm H2O) groups. Eighty percent of patients were ventilated using pressure control mode. Low, medium, and high Vt were applied to 10%, 43%, and 47% of patients, respectively. After correcting for patients requiring extracorporeal support, there was no difference in short-term to midterm outcomes among the different Vt groups. Low inflation pressures were applied to 61% of patients, who had a shorter length of intensive care unit stay (5 vs 12 days; P = .012), higher forced expiratory volume in 1 second at 3 months (77.8% vs 60.3%; P < .001), and increased 6-month survival rate (95% vs 77%; P = .008). Low Vt ventilation has not been fully adopted in our practice. Ventilation with higher inflation pressures, but not Vt, was significantly associated with poorer outcomes after lung transplantation. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Testing and Evaluation of the Bear Medical Systems, Inc. Bear 33 Volume Ventilator System

    Science.gov (United States)

    1990-12-01

    the ventilator and humidifier were attached to a Michigan Instruments Model 1600 mechanical lung analyzer, which simulated the patient’s lungs. We...AD-A241 836 USAFSAM-TR-90-22 TESTING AND EVALUATION OF THE BEAR MEDICAL SYSTEMS, INC. BEAR 33 VOLUME VENTILATOR SYSTEM Teresa R. Lewis, Captain, USAF...Medical Systems, Inc. PE - 62202F Bear 33 Volume Ventilator System PR - 7930 6. AUTHOR(S) TA - 16 WU - 12 Teresa R. Lewis, and Thomas E. Philbeck, Jr. 7

  20. Classroom HVAC: Improving ventilation and saving energy -- field study plan

    Energy Technology Data Exchange (ETDEWEB)

    Apte, Michael G.; Faulkner, David; Hodgson, Alfred T.; Sullivan, Douglas P.

    2004-10-14

    The primary goals of this research effort are to develop, evaluate, and demonstrate a very practical HVAC system for classrooms that consistently provides classrooms (CRs) with the quantity of ventilation in current minimum standards, while saving energy, and reducing HVAC-related noise levels. This research is motivated by the public benefits of energy efficiency, evidence that many CRs are under-ventilated, and public concerns about indoor environmental quality in CRs. This document provides a summary of the detailed plans developed for the field study that will take place in 2005 to evaluate the energy and IAQ performance of a new classroom HVAC technology. The field study will include measurements of HVAC energy use, ventilation rates, and IEQ conditions in 10 classrooms with the new HVAC technology and in six control classrooms with a standard HVAC system. Energy use and many IEQ parameters will be monitored continuously, while other IEQ measurements will be will be performed seasonally. Continuously monitored data will be remotely accessed via a LonWorks network. Instrument calibration plans that vary with the type of instrumentation used are established. Statistical tests will be employed to compare energy use and IEQ conditions with the new and standard HVAC systems. Strengths of this study plan include the collection of real time data for a full school year, the use of high quality instrumentation, the incorporation of many quality control measures, and the extensive collaborations with industry that limit costs to the sponsors.

  1. Determinants of ventilation behavior in naturally ventilated dwellings: Identification and quantification of relationships

    NARCIS (Netherlands)

    Levie, D.; Kluizenaar, Y. de; Hoes-van Oeffelen, E.C.M.; Hofstetter, H.; Janssen, S.A.; Spiekman, M.E.; Koene, F.G.H.

    2014-01-01

    Background: Ventilation in dwellings is essential for well-being and health. However, insight in determinants of ventilation behavior is still limited. Aim: Identifying determinants of ventilation behavior and quantifying relationships. Secondly, identifying households characteristics associated

  2. Carbon dioxide production during mechanical ventilation

    DEFF Research Database (Denmark)

    Henneberg, S; Söderberg, D; Groth, T

    1987-01-01

    Because of large stores of CO2 in different body tissues, metabolic change cannot be detected by measuring gas exchange until the CO2 stores have adapted to the new situation. Similarly, changes in the CO2 stores not due to metabolic alterations, may lead to error in gas exchange measurements. We...... continuously by a mass spectrometer. Signals from this instrument, together with gas-volume signals from the ventilator, were fed to a computer for calculation of VO2 and VCO2. Twenty to 120 min were required to reach a stable level, depending on the patient's size and circulatory response. Similar results...... and awareness. Ventilatory variables should not be changed substantially during the 90-min period before gas sampling. Cardiac output and muscle blood flow should not have changed 2 to 3 h before measuring RQ. If muscle blood flow is low, the stable periods for body temperature and ventilatory variables should...

  3. C-106 tank process ventilation test

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, J.W.

    1998-07-20

    Project W-320 Acceptance Test Report for tank 241-C-106, 296-C-006 Ventilation System Acceptance Test Procedure (ATP) HNF-SD-W320-012, C-106 Tank Process Ventilation Test, was an in depth test of the 296-C-006 ventilation system and ventilation support systems required to perform the sluicing of tank C-106. Systems involved included electrical, instrumentation, chiller and HVAC. Tests began at component level, moved to loop level, up to system level and finally to an integrated systems level test. One criteria was to perform the test with the least amount of risk from a radioactive contamination potential stand point. To accomplish this a temporary configuration was designed that would simulate operation of the systems, without being connected directly to the waste tank air space. This was done by blanking off ducting to the tank and connecting temporary ducting and an inlet air filter and housing to the recirculation system. This configuration would eventually become the possible cause of exceptions. During the performance of the test, there were points where the equipment did not function per the directions listed in the ATP. These events fell into several different categories. The first and easiest problems were field configurations that did not match the design documentation. This was corrected by modifying the field configuration to meet design documentation and reperforming the applicable sections of the ATP. A second type of problem encountered was associated with equipment which did not operate correctly, at which point an exception was written against the ATP, to be resolved later. A third type of problem was with equipment that actually operated correctly but the directions in the ATP were in error. These were corrected by generating an Engineering Change Notice (ECN) against the ATP. The ATP with corrected directions was then re-performed. A fourth type of problem was where the directions in the ATP were as the equipment should operate, but the design of

  4. Impact of Fire Ventilation on General Ventilation in the Building

    Science.gov (United States)

    Zender-Świercz, Ewa; Telejko, Marek

    2017-10-01

    The fire of building is a threat to its users. The biggest threat is generation, during lifetime of fire, hot gases and smoke. The purpose of quick and efficient evacuation from the area covered by the fire, at first step the escape routes have to be secured from smokiness. The smoke ventilation systems are used for this purpose. The proper design and execution of smoke ventilation is important not only because of the safety, but also of the maintenance of comfort in the building at a time when there is no fire. The manuscript presents the effect of incorrectly realized smoke ventilation in the stairwell of the medium building. The analysis shows that the flaps of smoke ventilation located in the stairwell may have a significant impact on the proper functioning of mechanical ventilation in the period when there is no fire. The improperly installed or incorrect insulated components cause perturbation of air flow and they change pressure distribution in the building. The conclusion of the analysis is the need to include the entire technical equipment of the building during the design and realization of its individual elements. The impact of various installations at each other is very important, and the omission of any of them can cause disturbances in the proper work of another.

  5. Tidal ventilation distribution during pressure-controlled ventilation and pressure support ventilation in post-cardiac surgery patients.

    Science.gov (United States)

    Blankman, P; VAN DER Kreeft, S M; Gommers, D

    2014-09-01

    Inhomogeneous ventilation is an important contributor to ventilator-induced lung injury. Therefore, this study examines homogeneity of lung ventilation by means of electrical impedance tomography (EIT) measurements during pressure-controlled ventilation (PCV) and pressure support ventilation (PSV) using the same ventilation pressures. Twenty mechanically ventilated patients were studied after cardiac surgery. On arrival at the intensive care unit, ventilation distribution was measured with EIT just above the diaphragm for 15 min. After awakening, PCV was switched to PSV and EIT measurements were again recorded. Tidal impedance variation, a measure of tidal volume, increased during PSV compared with PCV, despite using the same ventilation pressures (P = 0.045). The distribution of tidal ventilation to the dependent lung region was more pronounced during PSV compared with PCV, especially during the first half of the inspiration. An even distribution of tidal ventilation between the dependent and non-dependent lung regions was seen during PCV at lower tidal volumes (ventilation was predominantly distributed to the dependent lung during PSV at low tidal volumes. In post-cardiac surgery patients, PSV showed improved ventilation of the dependent lung region due to the contribution of the diaphragm activity, which is even more pronounced during lower assist levels. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  6. Ventilation systems for high halls

    Energy Technology Data Exchange (ETDEWEB)

    Sodec, F.; Veldboer, W.

    1982-02-01

    A ventilation system for high halls is described which meets the demands of steady air flow in spite of inverse thermal currents, intensive ventilation of working areas during heating and cooling and ventilation free of draught. The main element of the ventilation system is the air outlet in the ceiling, with variable beam direction. The horizontal, rotated beams are superimposed by a vertical beam whose strength may be varied. This way, the beam direction can be adapted to the thermal load of the hall and the height of blowout. The blowout angle is large for heating and small for cooling. Studies have shown that halls are ventilated thoroughly and free of draught by this system. The variable, rotary outlet presented in the article is best suited for heights of 4.00 to 12.00 m. The outlet, with a rated diameter of 400 mm, has been in use for two years now in fields as varied as diecasting works, halls at fairs, sports halls, etc. The air volume flow rate is 1000 to 3000 m/sup 3//h per outlet. A bigger version is now being developed; it will have a rated diameter of 710 mm and an air volume flow rate of 3000 to 9000 m/sup 3//h.

  7. Residential ventilation standards scoping study

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.; Sherman, Max H.

    2003-10-01

    The goals of this scoping study are to identify research needed to develop improved ventilation standards for California's Title 24 Building Energy Efficiency Standards. The 2008 Title 24 Standards are the primary target for the outcome of this research, but this scoping study is not limited to that timeframe. We prepared this scoping study to provide the California Energy Commission with broad and flexible options for developing a research plan to advance the standards. This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the ventilation needs of California residences, determining the bases for setting residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and corresponding levels of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

  8. Air Distribution in a Furnished Room Ventilated by Mixing Ventilation

    DEFF Research Database (Denmark)

    Nielsen, June Richter; Nielsen, Peter V.; Svidt, Kjeld

    Using isothermal full-scale experiments and two-dimensional isothermal CFD simulations it is investigated how normal office furniture influences the air movements in a room with mixing ventilation. Three different set-ups are made in the experiments and different sizes and locations of the furnit......Using isothermal full-scale experiments and two-dimensional isothermal CFD simulations it is investigated how normal office furniture influences the air movements in a room with mixing ventilation. Three different set-ups are made in the experiments and different sizes and locations...... of the furniture volume are simulated. The simulations are made in three different lengths of the room....

  9. Pneumoperitoneum associated with artificial ventilation.

    Science.gov (United States)

    Summers, B

    1979-06-09

    Four adults injured in serious road-traffic accidents developed pneumoperitoneum after artificial ventilation. No case could be attributed to injury or to perforation of a hollow viscus in the belly, but doubt about this in one patient resulted in exploratory laparotomy. In three patients the origin of intraperitoneal air was considered to be leakage through minute ruptures in alveoli subjected to the stress of artificial ventilation, with air tracking to the mediastinum, pleural space, subcutaneous tissues of the neck and chest, and peritoneal cavity. The fourth patient later developed herniation of the stomach through a rupture in the diaphragm, the presence of a pneumothorax on the same side suggesting direct passage of air through the diaphragm. Pneumoperitoneum induced by artificial ventilation is probably more common than reports suggest and should be distinguished clinically and radiologically from that caused by rupture or perforation of a hollow viscus. This will reduce the number of needles laparotomies performed on patients who are already seriously ill.

  10. Testing of mechanical ventilators and infant incubators in healthcare institutions.

    Science.gov (United States)

    Badnjevic, Almir; Gurbeta, Lejla; Jimenez, Elvira Ruiz; Iadanza, Ernesto

    2017-01-01

    The medical device industry has grown rapidly and incessantly over the past century. The sophistication and complexity of the designed instrumentation is nowadays rising and, with it, has also increased the need to develop some better, more effective and efficient maintenance processes, as part of the safety and performance requirements. This paper presents the results of performance tests conducted on 50 mechanical ventilators and 50 infant incubators used in various public healthcare institutions. Testing was conducted in accordance to safety and performance requirements stated in relevant international standards, directives and legal metrology policies. Testing of output parameters for mechanical ventilators was performed in 4 measuring points while testing of output parameters for infant incubators was performed in 7 measuring points for each infant incubator. As performance criteria, relative error of output parameters for mechanical ventilators and absolute error of output parameters for infant incubators was calculated. The ranges of permissible error, for both groups of devices, are regulated by the Rules on Metrological and Technical Requirements published in the Official Gazette of Bosnia and Herzegovina No. 75/14, which are defined based on international recommendations, standards and guidelines. All ventilators and incubators were tested by etalons calibrated in an ISO 17025 accredited laboratory, which provides compliance to international standards for all measured parameters.The results show that 30% of the tested medical devices are not operating properly and should be serviced, recalibrated and/or removed from daily application.

  11. [Mechanical ventilation in pediatrics (III). Weaning, complications and other types of ventilation. Noninvasive ventilation].

    Science.gov (United States)

    Pons Odena, M; Cambra Lasaosa, F J

    2003-08-01

    Noninvasive ventilation (NIV), i.e. without tracheal intubation, has been reintroduced for the treatment of respiratory failure to reduce the complications of mechanical ventilation. Nowadays, NIV with positive pressure is the preferred method, applied through a mask held in place by a harness. Several masks can be used (nasal, bucconasal facial) and a variety of means can be used to keep them in place. Many respirators can be selected, ranging from those traditionally used in the intensive care unit(ICU) to specific NV respirators and conventional ICU respirators with specific software for NIV. Many respiratory modalities can be used according to the respirator (biphasic positive airway pressure [BIPAP], proportional assist ventilation, pressure support, synchronized intermittent mandatory ventilation [SIMV], etc.). NIV is mainly indicated in exacerbations of chronic respiratory failure: neuromuscular diseases, pretransplantation cystic fibrosis, and obstructive sleep apnea syndrome. It is also indicated in acute respiratory failure: pneumonia, status asthmaticus, and acute lung edema. The main contraindications are a weakened airway protection reflex(absent cough reflex) and hemodynamic instabiity. The advantages of NIV derive mainly from avoiding the complications associated with invasive ventilation. NIV also presents some disadvantages, especially the greater workload involved to ensure good patient adaptation to the respirator. The most common sequelae of NIV are skin lesions due to pressure on the nasal bridge.

  12. [Pressure support ventilation and proportional assist ventilation during weaning from mechanical ventilation].

    Science.gov (United States)

    Aguirre-Bermeo, H; Bottiroli, M; Italiano, S; Roche-Campo, F; Santos, J A; Alonso, M; Mancebo, J

    2014-01-01

    To compare tolerance, duration of mechanical ventilation (MV) and clinical outcomes during weaning from MV in patients subjected to either pressure support ventilation (PSV) or proportional assist ventilation (PAV). A prospective, observational study was carried out. Intensive Care Unit. A total of 40 consecutive subjects were allocated to either the PSV or the PAV group until each group contained 20 patients. Patients were included in the study when they met the criteria to begin weaning and the attending physician decided to initiate the weaning process. The physician selected the modality and set the ventilatory parameters. None. Demographic data, respiratory mechanics, ventilatory parameters, duration of MV, and clinical outcomes (reintubation, tracheostomy, mortality). Baseline characteristics were similar in both groups. No significant differences were observed between the PSV and PAV groups in terms of the total duration of MV (10 [5-18] vs. 9 [7-19] days; P=.85), reintubation (5 [31%] vs. 3 [19%]; P=.69), or mortality (4 [20%] vs. 5 [25%] deaths; P=1). Eight patients (40%) in the PSV group and 6 patients (30%) in the PAV group (P=.74) required a return to volume assist-control ventilation due to clinical deterioration. Tolerance, duration of MV and clinical outcomes during weaning from mechanical ventilation were similar in PSV and PAV. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  13. Liquid lung ventilation as an alternative ventilatory support

    NARCIS (Netherlands)

    S.J.C. Verbrugge (Serge); D.A.M.P.J. Gommers (Diederik); B.F. Lachmann (Burkhard)

    1995-01-01

    textabstractThe concept of liquid ventilation has evolved in recent years into the concept of partial liquid ventilation. In this technique, conventional mechanical ventilation is combined with intratracheal perfluorocarbon administration. Partial liquid ventilation is a promising technique for

  14. Human versus Computer Controlled Selection of Ventilator Settings: An Evaluation of Adaptive Support Ventilation and Mid-Frequency Ventilation

    Science.gov (United States)

    Mireles-Cabodevila, Eduardo; Diaz-Guzman, Enrique; Arroliga, Alejandro C.; Chatburn, Robert L.

    2012-01-01

    Background. There are modes of mechanical ventilation that can select ventilator settings with computer controlled algorithms (targeting schemes). Two examples are adaptive support ventilation (ASV) and mid-frequency ventilation (MFV). We studied how different clinician-chosen ventilator settings are from these computer algorithms under different scenarios. Methods. A survey of critical care clinicians provided reference ventilator settings for a 70 kg paralyzed patient in five clinical/physiological scenarios. The survey-derived values for minute ventilation and minute alveolar ventilation were used as goals for ASV and MFV, respectively. A lung simulator programmed with each scenario's respiratory system characteristics was ventilated using the clinician, ASV, and MFV settings. Results. Tidal volumes ranged from 6.1 to 8.3 mL/kg for the clinician, 6.7 to 11.9 mL/kg for ASV, and 3.5 to 9.9 mL/kg for MFV. Inspiratory pressures were lower for ASV and MFV. Clinician-selected tidal volumes were similar to the ASV settings for all scenarios except for asthma, in which the tidal volumes were larger for ASV and MFV. MFV delivered the same alveolar minute ventilation with higher end expiratory and lower end inspiratory volumes. Conclusions. There are differences and similarities among initial ventilator settings selected by humans and computers for various clinical scenarios. The ventilation outcomes are the result of the lung physiological characteristics and their interaction with the targeting scheme. PMID:23119152

  15. Human versus Computer Controlled Selection of Ventilator Settings: An Evaluation of Adaptive Support Ventilation and Mid-Frequency Ventilation

    Directory of Open Access Journals (Sweden)

    Eduardo Mireles-Cabodevila

    2012-01-01

    Full Text Available Background. There are modes of mechanical ventilation that can select ventilator settings with computer controlled algorithms (targeting schemes. Two examples are adaptive support ventilation (ASV and mid-frequency ventilation (MFV. We studied how different clinician-chosen ventilator settings are from these computer algorithms under different scenarios. Methods. A survey of critical care clinicians provided reference ventilator settings for a 70 kg paralyzed patient in five clinical/physiological scenarios. The survey-derived values for minute ventilation and minute alveolar ventilation were used as goals for ASV and MFV, respectively. A lung simulator programmed with each scenario’s respiratory system characteristics was ventilated using the clinician, ASV, and MFV settings. Results. Tidal volumes ranged from 6.1 to 8.3 mL/kg for the clinician, 6.7 to 11.9 mL/kg for ASV, and 3.5 to 9.9 mL/kg for MFV. Inspiratory pressures were lower for ASV and MFV. Clinician-selected tidal volumes were similar to the ASV settings for all scenarios except for asthma, in which the tidal volumes were larger for ASV and MFV. MFV delivered the same alveolar minute ventilation with higher end expiratory and lower end inspiratory volumes. Conclusions. There are differences and similarities among initial ventilator settings selected by humans and computers for various clinical scenarios. The ventilation outcomes are the result of the lung physiological characteristics and their interaction with the targeting scheme.

  16. Ventilation effectiveness : health benefits of heat recovery ventilators

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-08-15

    Studies have shown that the installation of a heat recovery ventilator (HRV) in homes in northern Canada could improve indoor air quality and the respiratory health of inhabitants. Low ventilation rates are common in many homes in the North because the climate is severe, homes are smaller and lack basements, and occupancies are higher, leading to unhealthy indoor air quality. Northern communities also have a high rate of respiratory infections. HRVs recover much of the energy used to ventilate, which is desirable in cold regions with high heating costs. For the study, the test sample was divided into two types of houses, notably houses with active HRVs and those with control HRVs that were installed and operated but that did not function. The study results showed that HRVs provided increased ventilation. Complaints by residents about HRV noise, discomfort, or low humidity were common but equally spread between those with active and placebo HRVs. The study showed that the system design needs to be improved to better suit the needs of Inuit families. The nature of northern housing presents installation and maintenance challenges. It is hard to retrofit HRV ducting inside small, existing houses, and building supplies arrive infrequently, so detailed planning and careful take-offs of all supplies and materials must be done well in advance of construction. In addition, contractors are hard to locate and have variable expertise, and there is little technical follow-up. Robust technical support by local contractors and housing authorities is therefore important. 2 refs.

  17. The School Advanced Ventilation Engineering Software (SAVES)

    Science.gov (United States)

    The School Advanced Ventilation Engineering Software (SAVES) package is a tool to help school designers assess the potential financial payback and indoor humidity control benefits of Energy Recovery Ventilation (ERV) systems for school applications.

  18. Perioperative lung protective ventilation in obese patients

    NARCIS (Netherlands)

    Fernandez-Bustamante, Ana; Hashimoto, Soshi; Serpa Neto, Ary; Moine, Pierre; Vidal Melo, Marcos F.; Repine, John E.

    2015-01-01

    The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent

  19. Decisional responsibility for mechanical ventilation and weaning

    DEFF Research Database (Denmark)

    Rose, Louise; Blackwood, Bronagh; Egerod, Ingrid

    2011-01-01

    Optimal management of mechanical ventilation and weaning requires dynamic and collaborative decision making to minimize complications and avoid delays in the transition to extubation. In the absence of collaboration, ventilation decision making may be fragmented, inconsistent, and delayed. Our ob...

  20. Mechanisms of natural ventilation in livestock buildings

    DEFF Research Database (Denmark)

    Rong, Li; Bjerg, Bjarne Schmidt; Batzanas, Thomas

    2016-01-01

    Studies on the mechanisms of natural ventilation in livestock buildings are reviewed and influences on discharge and pressure coefficients are discussed. Compared to studies conducted on buildings for human occupation and industrial buildings which focus on thermal comfort, ventilation systems...

  1. FUNDAMENTALS OF THE THEORY OF VENTILLATION PROCESSES IN THE STEAM TURBINES TPP

    Directory of Open Access Journals (Sweden)

    V. M. Neuimin

    2015-01-01

    Full Text Available  The article proposes the theoretical framework of ventilation processes emerging and going on in the stages of TPP steam turbines during the operating regimes with small-quantity volumetric flow rates in the low-pressure cylinder. The basic theory includes new physicomathematical models for estimating the ventilating capacity losses and ventilation heatings-up of the steam and the air-gas channel of the turbine; search and investigation of the factors causing the increased momental loads on the blade wheels of the finale stages which are likely to lead to destruction of the rotating blades. The paper renders the practical results of utilizing the theoretical framework of ventilation processes.The author obtains a new mathematical relation for high-accuracy assessment of the ventilating capacity losses accounting for all the diversification of parameters defining the level of these losses (it is established that the Coriolis force contributes twice as much to the ventilating capacity losses as the centrifugal force. Seven ordinary formulae obtained on its basis provide a separate stage ventilation-losses immediate evaluation (with rotation blades of the finale stage not unwinding from the turning, with rotation blades of the finale and intermediate stages unwinding from the turning, in the turbine altogether-vapor-evacuated including by readings of the regular instruments located at the connecters of the exhaust part of the lowpressure cylinder.As the cornerstone of the new ventilation heating-up evaluation system the author lays two experimentally established facts: the ventilating capacity losses are practically constant at working steam negligible volumetric flow rates; symmetrical ventilating flows in the blade channel mingle entirely to the moment of their split up at the periphery. This renders possible estimating the complete enthalpy increment of the steam being discharged from a stage in relation to the enthalpy of the steam being

  2. Pressure support ventilation attenuates ventilator-induced protein modifications in the diaphragm

    OpenAIRE

    Powers, Scott K; DeCramer, Marc; Gayan-Ramirez, Ghislaine; Levine, Sanford

    2008-01-01

    Common medical conditions that require mechanical ventilation include chronic obstructive lung disease, acute lung injury, sepsis, heart failure, drug overdose, neuromuscular disorders, and surgery. Although mechanical ventilation can be a life saving measure, prolonged mechanical ventilation can also present clinical problems. Indeed, numerous well-controlled animal studies have demonstrated that prolonged mechanical ventilation results in diaphragmatic weakness due to both atrophy and contr...

  3. Newer nonconventional modes of mechanical ventilation

    OpenAIRE

    Preet Mohinder Singh; Anuradha Borle; Anjan Trikha

    2014-01-01

    The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient′s demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. ...

  4. Adequacy of Wind Ventilation in Upgraded Shelters.

    Science.gov (United States)

    1980-05-01

    etc. caused by atmospheric winds or thermal effects 2) Forced Ventilation - ventilation by artifical means using mechanical devices. If natural...through all the inlet or exit openings. The variation of ventilation throughput with the free stream wind velocity (V) is shown in araphical form in...ADEAUAC Y OF WIND VENTILATION IN UPGRADED SHELTERSG(U) NAY 80 R H HENNINGER, R J TSAL DCPAOI-78-C-0319 UNCLASSIFIED GARD-Al-11 (1713) NL

  5. Ventilation Host and Risk Area Techniques

    Science.gov (United States)

    1982-04-01

    is one option for ensuring that ventilation equipme is availabie during & crisis situation to shelters requiring mechanical ventilatioa. However...natural, wind-driven ventilation will suffice. However, for situations requiring mechanical ventilation to supply ad distribute air in shelters...Agency. DETACHABLE SUMMARY FINAL REPORT RTI/-072/O0-08F April 198• Ventilation : Most and Risk Area Technique. by S. B. York, 11I, K. J. Reeves, and R. J

  6. Evaluation of Shelter Ventilation by Model Tests

    Science.gov (United States)

    1983-03-01

    ventilation is created by mechanical devices such as pedal venti- lators and Kearny pumps. If natural ventilation in a shelter. can be predicted with...past have centered around the design, performance analysis and deployment of mechanical ventilating units (Ref. 11-14). Other studies include one on...calculated as the sum of the air volume flow rates through all the windward openings. The variation of model ventilation througnput versus wind speed

  7. Options for mechanical ventilation in neuromuscular diseases.

    Science.gov (United States)

    Unterborn, J N; Hill, N S

    1994-12-01

    A variety of mechanical devices may be used to provide assistance when ventilation and cough are severely impaired by progressive respiratory weakness caused by neuromuscular disease. Traditionally, positive pressure ventilation via a tracheostomy has been used, but if upper airway function is adequate, a variety of noninvasive devices also may be considered. Although positive pressure ventilation is the preferred noninvasive mode for assisting ventilation, other modes may be selected depending on patient needs, preferences, and physical characteristics.

  8. Luminescence Instrumentation

    DEFF Research Database (Denmark)

    Jain, Mayank; Bøtter-Jensen, Lars

    2014-01-01

    This chapter gives an introduction to instrumentation for stimulated luminescence studies, with special focus on luminescence dating using the natural dosimeters, quartz and feldspars. The chapter covers basic concepts in luminescence detection, and thermal and optical stimulation, and reference...... irradiation. It then briefly describes development of spectrometers in dating applications, and finally gives an overview of recent development in the field directly linked to novel instrumentation. Contents of Paper...

  9. Comparison of patient-ventilator asynchrony during pressure support ventilation and proportional assist ventilation modes in surgical Intensive Care Unit: A randomized crossover study

    OpenAIRE

    Parshotam Lal Gautam; Gaganjot Kaur; Sunil Katyal; Ruchi Gupta; Preetveen Sandhu; Nikhil Gautam

    2016-01-01

    Background: The patient-ventilator asynchrony is almost observed in all modes of ventilation, and this asynchrony affects lung mechanics adversely resulting in deleterious outcome. Innovations and advances in ventilator technology have been trying to overcome this problem by designing newer modes of ventilation. Pressure support ventilation (PSV) is a commonly used flow-cycled mode where a constant pressure is delivered by ventilator. Proportional assist ventilation (PAV) is a new dynamic ins...

  10. Neonatal mechanical ventilation: Indications and outcome

    OpenAIRE

    Qazi Iqbal; Mir M Younus; Asif Ahmed; Ikhlas Ahmad; Javed Iqbal; Bashir A Charoo; S Wajid Ali

    2015-01-01

    Background and Aims: Decreasing mortality in sick and ventilated neonates is an endeavor of all neonatologists. To reduce the high mortality in this group of neonates, identification of risk factors is important. This study was undertaken to find out the indications of ventilation and complications in ventilated neonates and also study possible predictors of outcome. Subjects: Age

  11. 14 CFR 252.9 - Ventilation systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ventilation systems. 252.9 Section 252.9... REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully functioning. Fully functioning for this purpose means operating so...

  12. 46 CFR 194.10-25 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... magazines. (1) All integral magazines shall be provided with natural or mechanical ventilation. Design... vans shall be provided with natural ventilation sufficient to maintain the inside air temperature below... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 194.10-25 Section 194.10-25 Shipping COAST...

  13. 46 CFR 98.25-75 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... shall be fitted with efficient natural or mechanical ventilation. (b) Enclosed compartments in which... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation. 98.25-75 Section 98.25-75 Shipping COAST... Ventilation. (a) All enclosed spaces containing cargo tanks fitted with bottom outlet connections shall be...

  14. Implementation of natural ventilation in pig houses

    NARCIS (Netherlands)

    Klooster, van 't C.E.

    1994-01-01

    A description of experimental work and discussion on implementation of natural ventilation in pig houses is given. A literature review describes the state of the art, animal growth data are given. It includes characterization of ventilation openings, a technique to estimate the ventilation

  15. Displacement Ventilation in Hospital Environments

    DEFF Research Database (Denmark)

    Li, Yuguo; Nielsen, Peter V.; Sandberg, Mats

    2011-01-01

    Hospital differ from conventional buildings in terms of ventilation needs. Exhaled infectious droplets or droplet nuclei of an infected patient need to be removed in general wards, waiting areas and isolation rooms to minimize transmission to health-care workers, other patients and visitors...

  16. Non-invasive mechanical ventilation

    African Journals Online (AJOL)

    Nicky

    2005-07-10

    Jul 10, 2005 ... Drinker P, McKahnn C. The use of a new apparatus for the prolonged administration of artificial respiration. JAMA 1929; 92: 1658-1660. 5. Emerson J. Some reflections on Iron Lungs and other inventions. Respiratory Care 1998;. 43: 574-583. 6. Brigg C. The benefits of non-invasive ventilation and CPAP ...

  17. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    The design of a displacement ventilation system involves determination of the flow rate in the thermal plumes. The flow rate in the plumes and the vertical temperature gradient influence each other, and they are influenced by many factors. This paper shows some descriptions of these effects....

  18. Cardiogenic oscillation induced ventilator autotriggering

    Directory of Open Access Journals (Sweden)

    Narender Kaloria

    2015-01-01

    Full Text Available Cardiogenic oscillation during mechanical ventilation can auto-trigger the ventilator resembling patient initiated breadth. This gives a false sense of intact respiratory drive and determination brain death, even if other tests are positive, is not appropriate in such a situation. It will prolong the ICU stay and confound the brain-death determination. In this case report, we describe a 35 year old man who was brought to the hospital after many hours of critical delay following multiple gun shot injuries. The patient suffered a cardiac arrest while on the way from another hospital. After an emergency laparotomy, patient was shifted to Intensive Care Unit (ICU with Glasgow Coma Scale (GCS score of E1VTM1 and was mechanically ventilated. Despite absence of brainstem reflexes, the ventilator continued to be triggered on continuous positive airway pressure (CPAP mode and the patient maintained normal oxygen saturation and acceptable levels of carbon dioxide. An apnoea test confirmed absent respiratory drive. Ventilatory waveform graph analysis, revealed cardiogenic oscillation as the cause for autotrigerring.

  19. Thermal Plumes in Ventilated Rooms

    DEFF Research Database (Denmark)

    Kofoed, Peter; Nielsen, Peter V.

    Ventilation systems with vertical displacement flow have been used in industrial areas with extensive heat loads for many years. Hot and contaminant air is carried directly from the occupied zone towards the ceiling by hot processes and other activities which create a natural convection flow....

  20. International Ventilation Cooling Application Database

    DEFF Research Database (Denmark)

    Holzer, Peter; Psomas, Theofanis Ch.; OSullivan, Paul

    2016-01-01

    The currently running International Energy Agency, Energy and Conservation in Buildings, Annex 62 Ventilative Cooling (VC) project, is coordinating research towards extended use of VC. Within this Annex 62 the joint research activity of International VC Application Database has been carried out, ...

  1. Ventilator-delivered mask ventilation compared with three standard methods of mask ventilation in a manikin model.

    Science.gov (United States)

    Tracy, M B; Klimek, J; Coughtrey, H; Shingde, V; Ponnampalam, G; Hinder, M; Maheshwari, R; Tracy, S K

    2011-05-01

    Little is known regarding the variations in effective ventilation during bag and mask resuscitation with standard methods compared with that delivered by ventilator-delivered mask ventilation (VDMV). To measure the variations in delivered airway pressure, tidal volume (TV), minute ventilation (MV) and inspiratory time during a 3-min period of mask ventilation comparing VDMV with three commonly used hand-delivered methods of bag and mask ventilation: Laerdal self-inflating bag (SIB); anaesthetic bag and T-piece Neopuff. A modified resuscitation manikin was used to measure variation in mechanical ventilation during 3-min periods of mask ventilation. Thirty-six experienced practitioners gave positive pressure mask ventilation targeting acceptable chest wall movement with a rate of 60 inflations/min and when pressures could be targeted or set, a peak inspiratory pressure (PIP) of 18 cm water, positive end-expiratory pressure (PEEP) of 5 cm water, for 3 min with each of the four mask ventilation methods. Each mode was randomly sequenced. A total of 21 136 inflations were recorded and analysed. VDMV achieved PIP and PEEP closest to that targeted and significantly lower variation in all measured parameters (pventilation on a manikin, VDMV produced the least variation in delivered ventilation. SIB produced wide variation and unacceptably high TV and MV in experienced hands.

  2. Comparison of various techniques for measuring natural ventilation in rooms

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Jarad, F. (University of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept of Physics); Sithamparanadarajah, R.; Thompson, J.M. (Birmingham Univ. (UK). Dept. of Physics); Fremlin, J.H. (Queen Elizabeth Hospital, Birmingham (UK))

    1982-11-01

    Various tracer gases were released into a room and the rate of decrease of their concentrations was used as a measure of the natural ventilation rate. Three different measurement instruments were used: an automated gas chromatograph, a gas sensor (for combustible gas), and a Geiger-Muller counter. The results of all three were in agreement. Complete mixing of all the tracers with the air inside the room required a period of at least 20 min. The organohalogenated gases were found to affect the results of the gas sensor because of their strong adsorption on its detector surface. Despite stratification, of both tracer gas concentration and air temperature, there was no significant effect on measurement of natural ventilation rate.

  3. Volume-Targeted Ventilation in the Neonate: Benchmarking Ventilators on an Active Lung Model.

    Science.gov (United States)

    Krieger, Tobias J; Wald, Martin

    2017-03-01

    Mechanically ventilated neonates have been observed to receive substantially different ventilation after switching ventilator models, despite identical ventilator settings. This study aims at establishing the range of output variability among 10 neonatal ventilators under various breathing conditions. Relative benchmarking test of 10 neonatal ventilators on an active neonatal lung model. Neonatal ICU. Ten current neonatal ventilators. Ventilators were set identically to flow-triggered, synchronized, volume-targeted, pressure-controlled, continuous mandatory ventilation and connected to a neonatal lung model. The latter was configured to simulate three patients (500, 1,500, and 3,500 g) in three breathing modes each (passive breathing, constant active breathing, and variable active breathing). Averaged across all weight conditions, the included ventilators delivered between 86% and 110% of the target tidal volume in the passive mode, between 88% and 126% during constant active breathing, and between 86% and 120% under variable active breathing. The largest relative deviation occurred during the 500 g constant active condition, where the highest output machine produced 147% of the tidal volume of the lowest output machine. All machines deviate significantly in volume output and ventilation regulation. These differences depend on ventilation type, respiratory force, and patient behavior, preventing the creation of a simple conversion table between ventilator models. Universal neonatal tidal volume targets for mechanical ventilation cannot be transferred from one ventilator to another without considering necessary adjustments.

  4. Influence of Persons' Movements on Ventilation Effectiveness

    DEFF Research Database (Denmark)

    Brohus, Henrik; Hyldig, Mikkel; Kamper, Simon

    2008-01-01

    Most often the ventilation effectiveness of a ventilated room is determined without considering the influence of persons´ movements. Even though the main reason for supplying the ventilation may be to create a healthy and productive environment for the occupants, their own influence...... on the ventilation is usually disregarded. This paper presents results from a systematic investigation of the movements´ influence on the ventilation effectiveness using human subjects combined with tracer gas measurements. Several typical "movements" are defined and carefully repeated to determine the influence......, even though the movements reduce the effectiveness. Furthermore, it is found that the influence of the different movements vary substantially....

  5. Instrumental Capital

    Directory of Open Access Journals (Sweden)

    Gabriel Valerio

    2007-07-01

    Full Text Available During the history of human kind, since our first ancestors, tools have represented a mean to reach objectives which might otherwise seemed impossibles. In the called New Economy, where tangibles assets appear to be losing the role as the core element to produce value versus knowledge, tools have kept aside man in his dairy work. In this article, the author's objective is to describe, in a simple manner, the importance of managing the organization's group of tools or instruments (Instrumental Capital. The characteristic conditions of this New Economy, the way Knowledge Management deals with these new conditions and the sub-processes that provide support to the management of Instrumental Capital are described.

  6. Instrumental aspects

    Science.gov (United States)

    Qureshi, Navid

    2017-10-01

    Every neutron scattering experiment requires the choice of a suited neutron diffractometer (or spectrometer in the case of inelastic scattering) with its optimal configuration in order to accomplish the experimental tasks in the most successful way. Most generally, the compromise between the incident neutron flux and the instrumental resolution has to be considered, which is depending on a number of optical devices which are positioned in the neutron beam path. In this chapter the basic instrumental principles of neutron diffraction will be explained. Examples of different types of experiments and their respective expectable results will be shown. Furthermore, the production and use of polarized neutrons will be stressed.

  7. Clinical review: liberation from mechanical ventilation.

    Science.gov (United States)

    El-Khatib, Mohamad F; Bou-Khalil, Pierre

    2008-01-01

    Mechanical ventilation is the defining event of intensive care unit (ICU) management. Although it is a life saving intervention in patients with acute respiratory failure and other disease entities, a major goal of critical care clinicians should be to liberate patients from mechanical ventilation as early as possible to avoid the multitude of complications and risks associated with prolonged unnecessary mechanical ventilation, including ventilator induced lung injury, ventilator associated pneumonia, increased length of ICU and hospital stay, and increased cost of care delivery. This review highlights the recent developments in assessing and testing for readiness of liberation from mechanical ventilation, the etiology of weaning failure, the value of weaning protocols, and a simple practical approach for liberation from mechanical ventilation.

  8. Short-term airing by natural ventilation

    DEFF Research Database (Denmark)

    Perino, Marco; Heiselberg, Per

    2009-01-01

    traditional mechanical ventilation components with natural ventilation devices, such as motorized windows and louvers. Among the various ventilation strategies that are currently available, buoyancy driven single-sided natural ventilation has proved to be very effective and can provide high air change rates...... that was aimed at developing and validating numerical models for the analysis of buoyancy driven single-sided natural ventilation systems. Once validated, these models can be used to optimize control strategies in order to achieve satisfactory indoor comfort conditions and IAQ.......The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. This kind of system frequently integrates...

  9. Music preferences of mechanically ventilated patients participating in a randomized controlled trial.

    Science.gov (United States)

    Heiderscheit, Annie; Breckenridge, Stephanie J; Chlan, Linda L; Savik, Kay

    2014-01-01

    Mechanical ventilation (MV) is a life-saving measure and supportive modality utilized to treat patients experiencing respiratory failure. Patients experience pain, discomfort, and anxiety as a result of being mechanically ventilated. Music listening is a non-pharmacological intervention used to manage these psychophysiological symptoms associated with mechanical ventilation. The purpose of this secondary analysis was to examine music preferences of 107 MV patients enrolled in a randomized clinical trial that implemented a patient-directed music listening protocol to help manage the psychophysiological symptom of anxiety. Music data presented includes the music genres and instrumentation patients identified as their preferred music. Genres preferred include: classical, jazz, rock, country, and oldies. Instrumentation preferred include: piano, voice, guitar, music with nature sounds, and orchestral music. Analysis of three patients' preferred music received throughout the course of the study is illustrated to demonstrate the complexity of assessing MV patients and the need for an ongoing assessment process.

  10. Music preferences of mechanically ventilated patients participating in a randomized controlled trial

    Science.gov (United States)

    Heiderscheit, Annie; Breckenridge, Stephanie J.; Chlan, Linda L.; Savik, Kay

    2014-01-01

    Mechanical ventilation (MV) is a life-saving measure and supportive modality utilized to treat patients experiencing respiratory failure. Patients experience pain, discomfort, and anxiety as a result of being mechanically ventilated. Music listening is a non-pharmacological intervention used to manage these psychophysiological symptoms associated with mechanical ventilation. The purpose of this secondary analysis was to examine music preferences of 107 MV patients enrolled in a randomized clinical trial that implemented a patient-directed music listening protocol to help manage the psychophysiological symptom of anxiety. Music data presented includes the music genres and instrumentation patients identified as their preferred music. Genres preferred include: classical, jazz, rock, country, and oldies. Instrumentation preferred include: piano, voice, guitar, music with nature sounds, and orchestral music. Analysis of three patients’ preferred music received throughout the course of the study is illustrated to demonstrate the complexity of assessing MV patients and the need for an ongoing assessment process. PMID:25574992

  11. Liquid ventilator for ultrafast hypothermia induction in juvenile lambs: Preliminary results.

    Science.gov (United States)

    Nadeau, Mathieu; Sage, Michaël; Kohlhauer, Matthias; Robert, Raymond; Vandamne, Jonathan; Mousseau, Julien; Tissier, Renaud; Praud, Jean-Paul; Walti, Hervé; Micheau, Philippe

    2015-08-01

    Total liquid ventilation (TLV) is an emerging mechanical ventilation technique. In this technique, the lungs are filled with liquid perfluorocarbons (PFC) and a liquid ventilator assures ventilation by periodically renewing a volume of oxygenated, CO2 freed and temperature controlled PFC. A huge difference between conventional mechanical ventilation and TLV relates to the fact that PFCs are about 1500 times denser than air. Thus, the PFCs filled lungs turn into an efficient heat exchanger with the circulating blood. One of the most appealing utilization of the lungs as a heat exchanger in TLV is for ultrafast induction of mild therapeutic hypothermia (MTH) for neuroprotection and cardioprotection after ischemia-reperfusion injuries. This study aimed to perform ultrafast MTH induction by TLV in animals up to 25 kg, then perform a fast post-hypothermic rewarming while maintaining proper ventilation. A thermal model of the lamb and liquid ventilator was developed to predict the dynamic and the control strategy to adopt for MTH induction. Two juvenile lambs were instrumented with temperature sensors in the femoral artery, pulmonary artery, oesophagus, right eardrum and rectum. After stabilization in conventional mechanical ventilation, TLV was initiated with ultrafast MTH induction, followed by posthypothermic rewarming. Preliminary results in the two juvenile lambs reveal that the liquid ventilator Inolivent-6.0 can induce MTH by TLV in less than 2.5 min for systemic arterial blood and in less than 10 min for venous return, esophagus and eardrum. Rectal temperature reached MTH in respectively 19.4 and 17.0 min for both lambs. Experimental results were consistent with the model predictions. Moreover, blood gas analysis exhibited that the gas exchange in the lungs was maintained adequately for the entire experiments.

  12. Summary of human responses to ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Seppanen, Olli A.; Fisk, William J.

    2004-06-01

    The effects of ventilation on indoor air quality and health is a complex issue. It is known that ventilation is necessary to remove indoor generated pollutants from indoor air or dilute their concentration to acceptable levels. But, as the limit values of all pollutants are not known, the exact determination of required ventilation rates based on pollutant concentrations and associated risks is seldom possible. The selection of ventilation rates has to be based also on epidemiological research (e.g. Seppanen et al., 1999), laboratory and field experiments (e.g. CEN 1996, Wargocki et al., 2002a) and experience (e.g. ECA 2003). Ventilation may also have harmful effects on indoor air quality and climate if not properly designed, installed, maintained and operated as summarized by Seppdnen (2003). Ventilation may bring indoors harmful substances that deteriorate the indoor environment. Ventilation also affects air and moisture flow through the building envelope and may lead to moisture problems that deteriorate the structures of the building. Ventilation changes the pressure differences over the structures of building and may cause or prevent the infiltration of pollutants from structures or adjacent spaces. Ventilation is also in many cases used to control the thermal environment or humidity in buildings. Ventilation can be implemented with various methods which may also affect health (e.g. Seppdnen and Fisk, 2002, Wargocki et al., 2002a). In non residential buildings and hot climates, ventilation is often integrated with air-conditioning which makes the operation of ventilation system more complex. As ventilation is used for many purposes its health effects are also various and complex. This paper summarizes the current knowledge on positive and negative effects of ventilation on health and other human responses. The focus of the paper is on office-type working environment and residential buildings. In the industrial premises the problems of air quality are usually

  13. Non-invasive Mechanical Ventilation Enhances Patient Autonomy in Decision-Making Regarding Chronic Ventilation.

    Science.gov (United States)

    Sviri, S; Linton, D M; van Heerden, P V

    2005-06-01

    Patients with respiratory failure due to progressive muscle weakness often require chronic ventilatory support, but many do not make decisions regarding ventilation prior to a crisis. We studied the use of non-invasive ventilation as a tool to enable communication and facilitate decision-making regarding chronic ventilation. Patients with profound muscle weakness and acute respiratory failure, were supported or weaned by non-invasive positive or negative pressure ventilation. The patients were then interviewed and their informed autonomous decisions were used to plan their future management. Non-invasive ventilation could be used safely to support patients with acute respiratory failure until decisions regarding chronic ventilation are made and as an alternative means of ventilation for those who refuse tracheostomy. Non-invasive ventilation may be used in patients with profound muscle weakness, as a means of enhancing patient autonomy by improving communication and maintaining ventilation until decisions about ongoing care are made.

  14. Assist-control mechanical ventilation attenuates ventilator-induced diaphragmatic dysfunction.

    Science.gov (United States)

    Sassoon, Catherine S H; Zhu, Ercheng; Caiozzo, Vincent J

    2004-09-15

    Controlled mechanical ventilation induced a profound diaphragm muscle dysfunction and atrophy. The effects of diaphragmatic contractions with assisted mechanical ventilation on diaphragmatic isometric, isotonic contractile properties, or the expression of muscle atrophy factor-box (MAF-box), the gene responsible for muscle atrophy, are unknown. We hypothesize that assisted mechanical ventilation will preserve diaphragmatic force and prevent overexpression of MAF-box. Studying sedated rabbits randomized equally into control animals, those with 3 days of assisted ventilation, and those with controlled ventilation, we assessed in vitro diaphragmatic isometric and isotonic contractile function. The concentrations of contractile proteins, myosin heavy chain isoform, and MAF-box mRNA were measured. Tetanic force decreased by 14% with assisted ventilation and 48% with controlled ventilation. Maximum shortening velocity tended to increase with controlled compared with assisted ventilation and control. Peak power output decreased 20% with assisted ventilation and 41% with controlled ventilation. Contractile proteins were unchanged with either modes of ventilation; myosin heavy chain 2X mRNA tended to increase and that of 2A to decrease with controlled ventilation. MAF-box gene was overexpressed with controlled ventilation. We conclude that preserving diaphragmatic contractions during mechanical ventilation attenuates the force loss induced by complete inactivity and maintains MAF-box gene expression in control.

  15. RHIC instrumentation

    Science.gov (United States)

    Shea, T. J.; Witkover, R. L.

    1998-12-01

    The Relativistic Heavy Ion Collider (RHIC) consists of two 3.8 km circumference rings utilizing 396 superconducting dipoles and 492 superconducting quadrupoles. Each ring will accelerate approximately 60 bunches of 1011 protons to 250 GeV, or 109 fully stripped gold ions to 100 GeV/nucleon. Commissioning is scheduled for early 1999 with detectors for some of the 6 intersection regions scheduled for initial operation later in the year. The injection line instrumentation includes: 52 beam position monitor (BPM) channels, 56 beam loss monitor (BLM) channels, 5 fast integrating current transformers and 12 video beam profile monitors. The collider ring instrumentation includes: 667 BPM channels, 400 BLM channels, wall current monitors, DC current transformers, ionization profile monitors (IPMs), transverse feedback systems, and resonant Schottky monitors. The use of superconducting magnets affected the beam instrumentation design. The BPM electrodes must function in a cryogenic environment and the BLM system must prevent magnet quenches from either fast or slow losses with widely different rates. RHIC is the first superconducting accelerator to cross transition, requiring close monitoring of beam parameters at this time. High space-charge due to the fully stripped gold ions required the IPM to collect magnetically guided electrons rather than the conventional ions. Since polarized beams will also be accelerated in RHIC, additional constraints were put on the instrumentation. The orbit must be well controlled to minimize depolarizing resonance strengths. Also, the position monitors must accommodate large orbit displacements within the Siberian snakes and spin rotators. The design of the instrumentation will be presented along with results obtained during bench tests, the injection line commissioning, and the first sextant test.

  16. Development of a Residential Integrated Ventilation Controller

    Energy Technology Data Exchange (ETDEWEB)

    Staff Scientist; Walker, Iain; Sherman, Max; Dickerhoff, Darryl

    2011-12-01

    The goal of this study was to develop a Residential Integrated Ventilation Controller (RIVEC) to reduce the energy impact of required mechanical ventilation by 20percent, maintain or improve indoor air quality and provide demand response benefits. This represents potential energy savings of about 140 GWh of electricity and 83 million therms of natural gas as well as proportional peak savings in California. The RIVEC controller is intended to meet the 2008 Title 24 requirements for residential ventilation as well as taking into account the issues of outdoor conditions, other ventilation devices (including economizers), peak demand concerns and occupant preferences. The controller is designed to manage all the residential ventilation systems that are currently available. A key innovation in this controller is the ability to implement the concept of efficacy and intermittent ventilation which allows time shifting of ventilation. Using this approach ventilation can be shifted away from times of high cost or high outdoor pollution towards times when it is cheaper and more effective. Simulations, based on the ones used to develop the new residential ventilation requirements for the California Buildings Energy code, were used to further define the specific criteria and strategies needed for the controller. These simulations provide estimates of the energy, peak power and contaminant improvement possible for different California climates for the various ventilation systems. Results from a field test of the prototype controller corroborate the predicted performance.

  17. ROV [Remotely Operated Vehicle] inspection inside ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, R.E. [AEA Technology, Harwell (United Kingdom)

    1996-12-31

    An instrumentation package for carrying out visual inspections and radiation monitoring within radioactive duct-work has been developed. This paper describes the first application of the package in the main ventilation duct of the Dounreay fuel cycle area. The package was deployed via a commercial ROV within a duct consisting of two parallel runs, over 300 metres long, between 0.9 and 1.7 metres high and 1.1 metres wide. An integrated, computer-controlled station was used for data collection, recording in digital form and on video tape. (UK).

  18. Laser instrument

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, R.J.; Eagar, T.W.

    1986-04-08

    An instrument is described for intercepting a carbon dioxide incident laser beam after it has energized a desired surgical target site but before it energizes material adjacent to the surgical target site. The instrument consists of: a substrate means for transmitting energy received from a laser beam away from a surgical target site, the substrate means having a high thermal conductivity and an exterior surface; a coating means for absorbing laser energy at the wavelength of a carbon dioxide laser, the coating means covering substantially the entirety of the exterior surface of the substrate means and having a high absorptivity for energy at the wavelength of the incident laser beam; and, the coating means having thickness which is large enough to provide high absorptivity but small enough to permit absorbed energy to be readily transferred to the high conductivity substrate means, and the thickness of the coating means being not greater than 0.001 inch.

  19. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 μm were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the

  20. Instrumentation viewpoint

    OpenAIRE

    Sarti, Centro Tecnológico de Vilanova i la Geltrú

    2010-01-01

    Following our traditional edition line, on this issue our magazine presents the annual summary of the different projects and research activities developed by SARTI research group during 2011. The research projects undertaken by SARTI, in collaboration with other Spanish and international research teams, are linked to the development of instrumentation technology for marine applications, as well as for general industry. SARTI, as research group of the Universitat Politècnica de Cat...

  1. Effect of body position on ventilation distribution in ventilated preterm infants.

    Science.gov (United States)

    Hough, Judith L; Johnston, Leanne; Brauer, Sandy; Woodgate, Paul; Schibler, Andreas

    2013-02-01

    Positioning is considered vital to the maintenance of good lung ventilation by optimizing oxygen transport and gas exchange in ventilated premature infants. Previous studies suggest that the prone position is advantageous; however, no data exist on regional ventilation distribution for this age group. To investigate the effect of body position on regional ventilation distribution in ventilated and nonventilated preterm infants using electrical impedance tomography. Randomized crossover study design. Neonatal ICU. A total of 24 ventilated preterm infants were compared with six spontaneously breathing preterm infants. Random assignment of the order of the positions supine, prone, and quarter prone. Ventilation distribution was measured with regional impedance amplitudes and global inhomogeneity indices using electrical impedance tomography. In the spontaneously breathing infants, regional impedance amplitudes were increased in the posterior compared with the anterior lung (p < 0.01) and in the right compared with the left lung (p = 0.03). No differences were found in the ventilated infants. Ventilation was more inhomogeneous in the ventilated compared with the healthy infants (p < 0.01). Assessment of temporal regional lung filling showed that the posterior lung filled earlier than the anterior lung in the spontaneously breathing infants (p < 0.02) whereas in the in the ventilated infants the right lung filled before the left lung (p < 0.01). In contrast to previous studies showing that ventilation is distributed to the nondependent lung in infants and children, this study shows that gravity has little effect on regional ventilation distribution.

  2. Demand controlled ventilation in a bathroom

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig; Nielsen, Toke Rammer; Topp, Claus

    2008-01-01

    consumption during periods where the demand for ventilation is low and poor indoor climate during periods where the demand for ventilation is high. Controlling the ventilation rate by demand can improve the energy performance of the ventilation system and the indoor climate. This paper compares the indoor...... climate and energy consumption of a Constant Air Volume (CAV) system and a Demand Controlled Ventilation (DCV) system for two different bathroom designs. The air change rate of the CAV system corresponded to 0.5h-1. The ventilation rate of the DCV system was controlled by occupancy and by the relative....... The indoor climate and the energy consumption were estimated based on a simplified calculation of the variation of the water content within the bathroom during a day. The results showed that the DCV system controlled by occupancy and relative humidity had an improved energy performance and an improved indoor...

  3. Noninvasive ventilation for acute respiratory failure.

    Science.gov (United States)

    Jasmer, R M; Matthay, M A

    2000-01-01

    Noninvasive ventilation refers to any form of ventilatory support applied without the use of an endotracheal tube. It offers the potential to provide primary treatment for acute respiratory failure while avoiding complications associated with mechanical ventilation with endotracheal intubation. Noninvasive ventilation has been most commonly studied in hypercapnic respiratory failure. A review of randomized, controlled studies shows mixed results and methodologic limitations affect the interpretation of current evidence. Patient selection is clearly the most important issue in considering noninvasive ventilation for acute respiratory failure. Unfortunately, patients who benefit from noninvasive ventilation represent only a minority of the total group with any one disease, and thus it is difficult to make broad conclusions concerning applicability of this treatment modality. Future studies are needed to focus on determining the specific patient populations who will benefit the most, evaluating the optimal ventilatory mode and mask for providing noninvasive ventilation, and clarifying its impact on clinical outcomes.

  4. Patient-ventilator asynchrony during noninvasive ventilation: a bench and clinical study

    National Research Council Canada - National Science Library

    Carteaux, Guillaume; Lyazidi, Aissam; Cordoba-Izquierdo, Ana; Vignaux, Laurence; Jolliet, Philippe; Thille, Arnaud W; Richard, Jean-Christophe M; Brochard, Laurent

    2012-01-01

    ...—and dedicated NIV ventilators. First, a bench model simulating spontaneous breathing efforts was used to assess the respective impact of inspiratory and expiratory leaks on cycling and triggering functions in 19 ventilators...

  5. Luftkvalitet i nyere skoler uden mekanisk ventilation

    DEFF Research Database (Denmark)

    Aggerholm, Søren

    I skoler uden mekanisk ventilation må der udluftes konsekvent for at forbedre luftkvaliteten. Rapporten viser resultatet af målinger af kuldioxidkoncentrationen i fire skoler uden mekanisk ventilation og én skole med mekanisk udsugning. Kuldioxidkoncentrationen er brugt som indikator...... for luftkvaliteten. Rapporten beskriver desuden de energimæssige konsekvenser ved at etablere mekanisk ventilation. Resultaterne har især interesse for skoleforvaltninger og rådgivende teknikere....

  6. Predicting Ventilation Failure in Children with Inhalation Injury.

    Science.gov (United States)

    1994-08-01

    tracheobron- supported adequately by mechanical ventilation would chitis and oxygenation abnormalities after 2 to 4 weeks of allow rapid enrollment of...these patients in trials of mechanical ventilation . Ventilatory indexes obtained early in new support techniques such as extracorporeal CO2 the...not be adequately supported by mechanical ventilation after smoke monary ventilation , combined liquid-gas ventilation , inhalation injury. Early

  7. High-Frequency Percussive Ventilation and Low Tidal Volume Ventilation in Burns: A Randomized Controlled Trial

    Science.gov (United States)

    2010-01-01

    care units, high-frequency percussive ventilation is preferentially used to provide mechanical ventilation in support of patients with acute lung... mechanical ventilation were admitted to the burn intensive care unit. The study was conducted over a 3-yr period between April 2006 and May 2009. This trial...was registered with ClinicalTrials.gov as NCT00351741. Interventions: Subjects were randomly assigned to receive mechanical ventilation through a high

  8. Comparison of Work of Breathing During Mechanical Ventilation Using Assist Control and Intermittent Mandatory Ventilation

    Science.gov (United States)

    1994-07-19

    AD-A285 516 AD MIPR NO: 92MM2539 TITLE: COMPARISON OF WORK OF BREATHING DURING MECHANICAL VENTILATION USING ASSIST CONTROL AND INTERMITTENT MANDATORY...1993, for the subject MIPR, titled: Comparison of Work of Breathing During Mechanical Ventilation Using Assist Control and Intermittent Mandatory...MIPR 92MM2539, titled: Comparison of Work of Breathing During Mechanical Ventilation Using Assist Control and Intermittent Mandatory Ventilation . 2

  9. Neurally adjusted ventilatory assist: a ventilation tool or a ventilation toy?

    Science.gov (United States)

    Verbrugghe, Walter; Jorens, Philippe G

    2011-03-01

    Mechanical ventilation has, since its introduction into clinical practice, undergone a major evolution from controlled ventilation to various modes of assisted ventilation. Neurally adjusted ventilatory assist (NAVA) is the newest development. The implementation of NAVA requires the introduction of a catheter to measure the electrical activity of the diaphragm (EA(di)). NAVA relies, opposite to conventional assisted ventilation modes, on the EA(di) to trigger the ventilator breath and to adjust the ventilatory assist to the neural drive. The amplitude of the ventilator assist is determined by the instantaneous EA(di) and the NAVA level set by the clinician. The NAVA level amplifies the EA(di) signal and determines instantaneous ventilator assist on a breath-to-breath basis. Experimental and clinical data suggest superior patient-ventilator synchrony with NAVA. Patient-ventilator asynchrony is present in 25% of mechanically ventilated patients in the intensive care unit and may contribute to patient discomfort, sleep fragmentation, higher use of sedation, development of delirium, ventilator-induced lung injury, prolonged mechanical ventilation, and ultimately mortality. With NAVA, the reliance on the EA(di) signal, together with an intact ventilatory drive and intact breathing reflexes, allows integration of the ventilator in the neuro-ventilatory coupling on a higher level than conventional ventilation modes. The simple monitoring of the EA(di) signal alone may provide the clinician with important information to guide ventilator management, especially during the weaning process. Although, until now, little evidence proves the superiority of NAVA on clinically relevant end points, it seems evident that patient populations (eg, COPD and small children) with major patient-ventilator asynchrony may benefit from this new ventilatory tool.

  10. Concentration Distribution in a Mixing Ventilated Room

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Pedersen, D. N.; Nielsen, Peter Vilhelm

    2001-01-01

    Today there is an increasing focus on the importance of a proper ventilation system to obtain good working conditions in the term of air and thermal quality to ensure high productivity. Different ventilation principles are used, e.g., mixing ventilation and displacement ventilation. In order....... Full scale experiments along with a breathing thermal manikin (BTM) have been used. The results show that the location of the sources is of great importance, just as well as temperature differences. Furthermore, the concentration in the breathing zone showed large differences throughout the room....

  11. Sleep and Mechanical Ventilation in Critical Care.

    Science.gov (United States)

    Blissitt, Patricia A

    2016-06-01

    Sleep disturbances in critically ill mechanically ventilated patients are common. Although many factors may potentially contribute to sleep loss in critical care, issues around mechanical ventilation are among the more complex. Sleep deprivation has systemic effects that may prolong the need for mechanical ventilation and length of stay in critical care and result in worse outcomes. This article provides a brief review of the physiology of sleep, physiologic changes in breathing associated with sleep, and the impact of mechanical ventilation on sleep. A summary of the issues regarding research studies to date is also included. Recommendations for the critical care nurse are provided. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Mechanical ventilation of the anesthetized patient.

    Science.gov (United States)

    Damico, Nicole K

    2015-03-01

    Patients who require general anesthesia to undergo a surgical procedure often require mechanical ventilation during the perioperative period. Ventilators incorporated into modern anesthesia machines offer various options for patient management. The unique effects of general anesthesia and surgery on pulmonary physiology must be considered when selecting an individualized plan for mechanical ventilation during the perioperative period. In this article, the pulmonary effects of general anesthesia are reviewed and available options for mechanical ventilation of the anesthetized patient during the perioperative period are presented. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Concentration Distribution in a Mixing Ventilated Room

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Pedersen, D.N.; Nielsen, Peter V.

    2001-01-01

    Today there is an increasing focus on the importance of a proper ventilation system to obtain good working conditions in the term of air and thermal quality to ensure high productivity. Different ventilation principles are used, e.g., mixing ventilation and displacement ventilation. In order...... that the air is fully mixed. The objective of this work is to determine the influence of the location of a pollutant, temperature differences and whether the room is furnished or not. It is also investigated if it is sufficient to determine the mean concentration in the room to determine the personal exposure...

  14. Fractal nature of regional ventilation distribution.

    Science.gov (United States)

    Altemeier, W A; McKinney, S; Glenny, R W

    2000-05-01

    High-resolution measurements of pulmonary perfusion reveal substantial spatial heterogeneity that is fractally distributed. This observation led to the hypothesis that the vascular tree is the principal determinant of regional blood flow. Recent studies using aerosol deposition show similar ventilation heterogeneity that is closely correlated with perfusion. We hypothesize that ventilation has fractal characteristics similar to blood flow. We measured regional ventilation and perfusion with aerosolized and injected fluorescent microspheres in six anesthetized, mechanically ventilated pigs in both prone and supine postures. Adjacent regions were clustered into progressively larger groups. Coefficients of variation were calculated for each cluster size to determine fractal dimensions. At the smallest size lung piece, local ventilation and perfusion are highly correlated, with no significant difference between ventilation and perfusion heterogeneity. On average, the fractal dimension of ventilation is 1.16 in the prone posture and 1. 09 in the supine posture. Ventilation has fractal properties similar to perfusion. Efficient gas exchange is preserved, despite ventilation and perfusion heterogeneity, through close correlation. One potential explanation is the similar geometry of bronchial and vascular structures.

  15. [VENTILOP survey. Survey in peroperative mechanical ventilation].

    Science.gov (United States)

    Fischer, F; Collange, O; Mahoudeau, G; Simon, M; Moussa, H; Thibaud, A; Steib, A; Pottecher, T; Mertes, M

    2014-06-01

    Mechanical ventilation can initiate ventilator-associated lung injury and postoperative pulmonary complications. The aim of this study was to evaluate (1) how mechanical ventilation was comprehended by anaesthetists (physician and nurses) and (2) the need for educational programs. A computing questionnary was sent by electronic-mail to the entire anaesthetist from Alsace region in France (297 physicians), and to a pool of 99 nurse anaesthetists. Mechanical ventilation during anaesthesia was considered as optimized when low tidal volume (6-8mL) of ideal body weight was associated with positive end expiratory pressure, FiO2 less than 50%, I/E adjustment and recruitment maneuvers. The participation rate was 50.5% (172 professionals). Only 2.3% of professionals used the five parameters for optimized ventilation. Majority of professionals considered that mechanical ventilation adjustment influenced the patients' postoperative outcome. Majority of the professionals asked for a specific educational program in the field of mechanical ventilation. Only 2.3% of professionals optimized mechanical ventilation during anaesthesia. Guidelines and specific educational programs in the field of mechanical ventilation are widely expected. Copyright © 2014 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  16. Boundary conditions for the use of personal ventilation over mixing ventilation in open plan offices

    DEFF Research Database (Denmark)

    Petersen, Steffen; Hviid, Christian Anker

    2013-01-01

    This paper investigates the boundary conditions for choosing a combined Personal Ventilation (PV) and Mixing Ventilation (MV) over conventional mixing ventilation in an office with multiple workers. A simplified procedure for annual performance assessment of PV/MV systems in terms of air quality,...

  17. Ventilation strategies and outcome in randomised trials of high frequency ventilation

    OpenAIRE

    Thome, U; Carlo, W; Pohlandt, F

    2005-01-01

    Objective: Randomised controlled trials comparing elective use of high frequency ventilation (HFV) with conventional mechanical ventilation (CMV) in preterm infants have yielded conflicting results. We hypothesised that the variability of results may be explained by differences in study design, ventilation strategies, delay in initiation of HFV, and use of permissive hypercapnia.

  18. Aerosol delivery with two ventilation modes during mechanical ventilation: a randomized study.

    Science.gov (United States)

    Dugernier, Jonathan; Reychler, Gregory; Wittebole, Xavier; Roeseler, Jean; Depoortere, Virginie; Sottiaux, Thierry; Michotte, Jean-Bernard; Vanbever, Rita; Dugernier, Thierry; Goffette, Pierre; Docquier, Marie-Agnes; Raftopoulos, Christian; Hantson, Philippe; Jamar, François; Laterre, Pierre-François

    2016-12-01

    Volume-controlled ventilation has been suggested to optimize lung deposition during nebulization although promoting spontaneous ventilation is targeted to avoid ventilator-induced diaphragmatic dysfunction. Comparing topographic aerosol lung deposition during volume-controlled ventilation and spontaneous ventilation in pressure support has never been performed. The aim of this study was to compare lung deposition of a radiolabeled aerosol generated with a vibrating-mesh nebulizer during invasive mechanical ventilation, with two modes: pressure support ventilation and volume-controlled ventilation. Seventeen postoperative neurosurgery patients without pulmonary disease were randomly ventilated in pressure support or volume-controlled ventilation. Diethylenetriaminepentaacetic acid labeled with technetium-99m (2 mCi/3 mL) was administrated using a vibrating-mesh nebulizer (Aerogen Solo(®), provided by Aerogen Ltd, Galway, Ireland) connected to the endotracheal tube. Pulmonary and extrapulmonary particles deposition was analyzed using planar scintigraphy. Lung deposition was 10.5 ± 3.0 and 15.1 ± 5.0 % of the nominal dose during pressure support and volume-controlled ventilation, respectively (p ventilation (27.4 ± 6.6 vs. 20.7 ± 6.0 %, p ventilation modes. A high intersubject variability of lung deposition was observed with both modes regarding lung doses, aerosol penetration and distribution between the right and the left lung. In the specific conditions of the study, volume-controlled ventilation was associated with higher lung deposition of nebulized particles as compared to pressure support ventilation. The clinical benefit of this effect warrants further studies. Clinical trial registration NCT01879488.

  19. Frequently Asked Questions about Ventilator-Associated Pneumonia

    Science.gov (United States)

    ... Vaccine Safety Frequently Asked Questions about Ventilator-associated Pneumonia Recommend on Facebook Tweet Share Compartir What is a Ventilator-associated Pneumonia (VAP)? Ventilator-associated pneumonia (VAP) is a lung ...

  20. Performances of domiciliary ventilators compared by using a parametric procedure

    Directory of Open Access Journals (Sweden)

    Fresnel Emeline

    2016-12-01

    Performances of domiciliary ventilators strongly depend not only on the breathing dynamics but also on the ventilator strategy. One given ventilator may be more adequate than another one for a given patient.

  1. Neuromuscular paralysis for newborn infants receiving mechanical ventilation

    NARCIS (Netherlands)

    Cools, F.; Offringa, M.

    2005-01-01

    BACKGROUND: Ventilated newborn infants breathing in asynchrony with the ventilator are at risk for complications during mechanical ventilation, such as pneumothorax or intraventricular hemorrhage, and are exposed to more severe barotrauma, which consequently could impair their clinical outcome.

  2. Hypercapnia attenuates ventilator-induced diaphragm atrophy and modulates dysfunction

    NARCIS (Netherlands)

    Schellekens, W.J.M.; Hees, H.W.H. van; Kox, M.; Linkels, M.; Acuna, G.L.; Dekhuijzen, P.N.R.; Scheffer, G.J.; Hoeven, J.G. van der; Heunks, L.M.A.

    2014-01-01

    INTRODUCTION: Diaphragm weakness induced by prolonged mechanical ventilation may contribute to difficult weaning from the ventilator. Hypercapnia is an accepted side effect of low tidal volume mechanical ventilation, but the effects of hypercapnia on respiratory muscle function are largely unknown.

  3. Trends in mechanical ventilation: are we ventilating our patients in the best possible way?

    Directory of Open Access Journals (Sweden)

    Raffaele L. Dellaca’

    2017-06-01

    To learn how mechanical ventilation developed in recent decades and to provide a better understanding of the actual technology and practice. To learn how and why interdisciplinary research and competences are necessary for providing the best ventilation treatment to patients. To understand which are the most relevant technical limitations in modern mechanical ventilators that can affect their performance in delivery of the treatment. To better understand and classify ventilation modes. To learn the classification, benefits, drawbacks and future perspectives of automatic ventilation tailoring algorithms.

  4. Thermal comfort of seated occupants in rooms with personalized ventilation combined with mixing or displacement ventilation

    DEFF Research Database (Denmark)

    Forejt, L.; Melikov, Arsen Krikor; Cermak, Radim

    2004-01-01

    The performance of two personalized ventilation systems combined with mixing or displacement ventilation was studied under different conditions in regard to thermal comfort of seated occupants. The cooling performance of personalized ventilation was found to be independent of room air distribution....... Differences between the personalized air terminal devices were identified in terms of the cooling distribution over the manikin¿s body. The personalized ventilation supplying air from the front towards the face provided a more uniform cooling of the body than the personalized ventilation supplying air from...

  5. History of Mechanical Ventilation. From Vesalius to Ventilator-induced Lung Injury.

    Science.gov (United States)

    Slutsky, Arthur S

    2015-05-15

    Mechanical ventilation is a life-saving therapy that catalyzed the development of modern intensive care units. The origins of modern mechanical ventilation can be traced back about five centuries to the seminal work of Andreas Vesalius. This article is a short history of mechanical ventilation, tracing its origins over the centuries to the present day. One of the great advances in ventilatory support over the past few decades has been the development of lung-protective ventilatory strategies, based on our understanding of the iatrogenic consequences of mechanical ventilation such as ventilator-induced lung injury. These strategies have markedly improved clinical outcomes in patients with respiratory failure.

  6. Healthcare Technology Management (HTM) of mechanical ventilators by clinical engineers.

    Science.gov (United States)

    Yoshioka, Jun; Nakane, Masaki; Kawamae, Kaneyuki

    2014-01-01

    Mechanical ventilator failures expose patients to unacceptable risks, and maintaining mechanical ventilator safety is an important issue. We examined the usefulness of maintaining mechanical ventilators by clinical engineers (CEs) using a specialized calibrator. These evaluations and the ability to make in-house repairs proved useful for obviating the need to rent ventilators which, in turn, might prove faulty themselves. The CEs' involvement in maintaining mechanical ventilators is desirable, ensures prompt service, and, most importantly, enhances safe management of mechanical ventilators.

  7. Preoperational test report, primary ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Primary Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space filtered venting of tanks AY101, AY102, AZ101, AZ102. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  8. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas ov...

  9. YMP Engineered Barrier Systems Scaled Ventilation Testing

    Energy Technology Data Exchange (ETDEWEB)

    S.D. Dunn; B. Lowry; B. Walsh; J.D. Mar; C. Howard; R. Johnston; T. Williams

    2002-11-22

    Yucca Mountain, approximately 100 miles northwest of Las Vegas, Nevada, has been selected as the site for the nation's first geologic repository for high level nuclear waste. The Yucca Mountain Project (YMP) is currently developing the design for the underground facilities. Ventilation is a key component of the design as a way to maintain the desired thermal conditions in the emplacement drifts prior to closure. As a means of determining the effects of continuous ventilation on heat removal from the emplacement drifts two series of scaled ventilation tests have been performed. Both test series were performed in the DOE/North Las Vegas Atlas facility. The tests provided scaled (nominally 25% of the full scale emplacement drift design) thermal and flow process data that will be used to validate YMP heat and mass transport codes. The Phase I Ventilation Test series evaluated the ability of ambient ventilation air to remove energy under varying flow and input power conditions. The Phase II Ventilation Test series evaluated the ability of pre-conditioned ventilation air to remove energy under varying flow, input temperature and moisture content, and simulated waste package input power conditions. Twenty-two distinct ventilation tests were run.

  10. Hybrid ventilation systems and high performance buildings

    Energy Technology Data Exchange (ETDEWEB)

    Utzinger, D.M. [Wisconsin Univ., Milwaukee, WI (United States). School of Architecture and Urban Planning

    2009-07-01

    This paper described hybrid ventilation design strategies and their impact on 3 high performance buildings located in southern Wisconsin. The Hybrid ventilation systems combined occupant controlled natural ventilation with mechanical ventilation systems. Natural ventilation was shown to provide adequate ventilation when appropriately designed. Proper control integration of natural ventilation into hybrid systems was shown to reduce energy consumption in high performance buildings. This paper also described the lessons learned from the 3 buildings. The author served as energy consultant on all three projects and had the responsibility of designing and integrating the natural ventilation systems into the HVAC control strategy. A post occupancy evaluation of building energy performance has provided learning material for architecture students. The 3 buildings included the Schlitz Audubon Nature Center completed in 2003; the Urban Ecology Center completed in 2004; and the Aldo Leopold Legacy Center completed in 2007. This paper included the size, measured energy utilization intensity and percentage of energy supplied by renewable solar power and bio-fuels on site for each building. 6 refs., 2 tabs., 6 figs.

  11. Endotoxemia accelerates diaphragm dysfunction in ventilated rabbits.

    Science.gov (United States)

    Yang, Yi; Yu, Tao; Pan, Chun; Longhini, Federico; Liu, Ling; Huang, Yingzi; Guo, Fengmei; Qiu, Haibo

    2016-12-01

    Ventilators may induce diaphragm dysfunction, and most of the septic population who are admitted to the intensive care unit require mechanical ventilation. However, there is no evidence that sepsis accelerates the onset of ventilator-induced diaphragm dysfunction or affects the microcirculation. Our study investigated whether lipopolysaccharide (LPS)-induced endotoxemia accelerated diaphragm dysfunction in ventilated rabbits by evaluating microcirculation, lipid accumulation, and diaphragm contractility. After anesthesia and tracheostomy, 25 invasively monitored and mechanically ventilated New Zealand white rabbits were randomized to control (n = 5), controlled mechanical ventilation (CMV) (n = 5), pressure support ventilation (PSV; n = 5), CMV or PSV with LPS-induced endotoxemia (CMV-LPS and PSV-LPS, respectively; n = 5 for each). Rabbits were anesthetized and ventilated for 24 h, except the control rabbits (30 min). Diaphragmatic contractility was evaluated using neuromechanical and neuroventilatory efficiency. We evaluated the following at the end of the protocol: (1) diaphragm microcirculation; (2) lipid accumulation; and (3) diaphragm muscular fibers structure. Diaphragm contractility, microcirculation, lipid accumulation, and fiber structures were severely compromised in endotoxemic animals after 24 h compared to nonendotoxemic rabbits. Moreover, a slight but significant increase in lipid accumulation was observed in CMV and PSV groups compared with controls (P rabbits, affects the microcirculation, and results in diaphragmatic lipid accumulation and contractility impairment. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Simulating People Moving in Displacement Ventilated Rooms

    DEFF Research Database (Denmark)

    Mattsson, M.; Bjørn, Erik; Sandberg, M.

    A displacement ventilation system works better the more uni-directional the air flow through the ventilated room is: from floor to ceiling. Thus, from an air quality point of view, there should be as little vertical mixing of the room air as possible. It is therefore comprehensible that physical...

  13. Naturlig ventilation og træk

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    2002-01-01

    Nye ventilationsprincipper som naturlig ventilation er med til at sætte fokus på de strømningselementer, der skal anvendes til dimensionering af luftfordelingen i et rum. Artiklen anviser, hvordan træk fra vinduer og tagåbninger i rum med naturlig ventilation kan beregnes ved hjælp af...

  14. Echocardiographic evaluation during weaning from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Luciele Medianeira Schifelbain

    2011-01-01

    Full Text Available INTRODUCTION: Echocardiographic, electrocardiographic and other cardiorespiratory variables can change during weaning from mechanical ventilation. OBJECTIVES: To analyze changes in cardiac function, using Doppler echocardiogram, in critical patients during weaning from mechanical ventilation, using two different weaning methods: pressure support ventilation and T-tube; and comparing patient subgroups: success vs. failure in weaning. METHODS: Randomized crossover clinical trial including patients under mechanical ventilation for more than 48 h and considered ready for weaning. Cardiorespiratory variables, oxygenation, electrocardiogram and Doppler echocardiogram findings were analyzed at baseline and after 30 min in pressure support ventilation and T-tube. Pressure support ventilation vs. T-tube and weaning success vs. failure were compared using ANOVA and Student's t-test. The level of significance was p<0.05. RESULTS: Twenty-four adult patients were evaluated. Seven patients failed at the first weaning attempt. No echocardiographic or electrocardiographic differences were observed between pressure support ventilation and T-tube. Weaning failure patients presented increases in left atrium, intraventricular septum thickness, posterior wall thickness and diameter of left ventricle and shorter isovolumetric relaxation time. Successfully weaned patients had higher levels of oxygenation. CONCLUSION: No differences were observed between Doppler echocardiographic variables and electrocardiographic and other cardiorespiratory variables during pressure support ventilation and T-tube. However cardiac structures were smaller, isovolumetric relaxation time was larger, and oxygenation level was greater in successfully weaned patients

  15. Carbon dioxide production during mechanical ventilation

    DEFF Research Database (Denmark)

    Henneberg, S; Söderberg, D; Groth, T

    1987-01-01

    studied CO2 production (VCO2) and oxygen consumption (VO2) in mechanically ventilated ICU patients, where CO2 stores were altered by: a) changing minute ventilation by 15%, b) reducing body temperature, and c) changing the level of sedation. Expired gases went through a mixing chamber and were analyzed...

  16. New modes of assisted mechanical ventilation.

    Science.gov (United States)

    Suarez-Sipmann, F

    2014-05-01

    Recent major advances in mechanical ventilation have resulted in new exciting modes of assisted ventilation. Compared to traditional ventilation modes such as assisted-controlled ventilation or pressure support ventilation, these new modes offer a number of physiological advantages derived from the improved patient control over the ventilator. By implementing advanced closed-loop control systems and using information on lung mechanics, respiratory muscle function and respiratory drive, these modes are specifically designed to improve patient-ventilator synchrony and reduce the work of breathing. Depending on their specific operational characteristics, these modes can assist spontaneous breathing efforts synchronically in time and magnitude, adapt to changing patient demands, implement automated weaning protocols, and introduce a more physiological variability in the breathing pattern. Clinicians have now the possibility to individualize and optimize ventilatory assistance during the complex transition from fully controlled to spontaneous assisted ventilation. The growing evidence of the physiological and clinical benefits of these new modes is favoring their progressive introduction into clinical practice. Future clinical trials should improve our understanding of these modes and help determine whether the claimed benefits result in better outcomes. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  17. Evaporation Controlled Emission in Ventilated Rooms

    DEFF Research Database (Denmark)

    Topp, Claus; Nielsen, Peter V.; Heiselberg, Per

    -scale ventilated room when the emission is fully or partly evaporation controlled. The objective of the present research work has been to investigate the change of emission rates from small-scale experiments to full-scale ventilated rooms and to investigate the influence of the local air velocity field near...

  18. Assisted Ventilation in Patients with Acute Respiratory Distress Syndrome: Lung-distending Pressure and Patient-Ventilator Interaction

    NARCIS (Netherlands)

    Doorduin, J.; Sinderby, C.A.; Beck, J.; Hoeven, J.G. van der; Heunks, L.M.

    2015-01-01

    BACKGROUND: In patients with acute respiratory distress syndrome (ARDS), the use of assisted mechanical ventilation is a subject of debate. Assisted ventilation has benefits over controlled ventilation, such as preserved diaphragm function and improved oxygenation. Therefore, higher level of

  19. Effects of manual hyperinflation and suctioning in respiratory mechanics in mechanically ventilated patients with ventilator-associated pneumonia

    National Research Council Canada - National Science Library

    Choi, Jessica Siu-Ping; Jones, Alice Yee-Men

    2005-01-01

    ... in ventilator-associated pneumonia. Tracheal suction is often employed by nursing staff in the management of mechanically ventilated patients with ventilator-associated pneumonia but this technique has the potential to increase respiratory resistance...

  20. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    Directory of Open Access Journals (Sweden)

    Yan Shi

    2014-01-01

    Full Text Available Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of ventilator on the dynamics of the ventilated respiratory system are carried out. This study can be helpful in the VCV ventilation treatment and respiratory diagnostics.

  1. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over...... radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

  2. Short Term Airing by Natural Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Perino, M.

    2010-01-01

    that are currently available, buoyancy driven, single-sided natural ventilation has proved to be very effective and can provide high air change rates for temperature and Indoor Air Quality (IAQ) control. However, to promote a wider distribution of these systems an improvement in the knowledge of their working......The need to improve the energy efficiency of buildings requires new and more efficient ventilation systems. It has been demonstrated that innovative operating concepts that make use of natural ventilation seem to be more appreciated by occupants. Among the available ventilation strategies...... principles is necessary. The present study analyses and presents the results of an experimental evaluation of airing performance in terms of ventilation characteristics, IAQ and thermal comfort. It includes investigations of the consequences of opening time, opening frequency, opening area and expected...

  3. Functionality of Ventilated Facades: Protection of Insulation

    Directory of Open Access Journals (Sweden)

    Petrichenko Mikhail

    2016-01-01

    Full Text Available This article discusses about methods of construction of the ventilated facades. The ventilated facade is not only the element of facing, it is the supporting structure. Their main objective - creation of air ventilating space between a facade and an external wall of the building. Moving of air in this gap protects a heater from destruction, interfering with a moisture congestion. In addition, the ventilated facade protect the building from aggressive influence of external environment, have a sound and thermal insulation properties. There are several problems of systems of the ventilated facades connected with an application of a heater. For more effective using it is necessary to minimize contact of a heater with environment.

  4. Potential of Natural Ventilation in Shopping Centres

    DEFF Research Database (Denmark)

    Diederichsen, Alice; Friis, Kristina; Brohus, Henrik

    2008-01-01

    The indoor environmental quality (IEQ) is a fundamental requirement for a well performing shopping centre. This paper contains a pilot study of the potential of using hybrid ventilation (a combination of automatically controlled natural and mechanical ventilation - respectively NV and MV) in shop......The indoor environmental quality (IEQ) is a fundamental requirement for a well performing shopping centre. This paper contains a pilot study of the potential of using hybrid ventilation (a combination of automatically controlled natural and mechanical ventilation - respectively NV and MV......) in shopping centres with focus on both the achieved IEQ and energy consumptions for air movement. By thermal building simulations it is found that there exists an interesting potential for hybrid ventilation of shopping centres, which can lead to great savings in the electrical energy consumptions...

  5. Mechanical Ventilation: State of the Art.

    Science.gov (United States)

    Pham, Tài; Brochard, Laurent J; Slutsky, Arthur S

    2017-09-01

    Mechanical ventilation is the most used short-term life support technique worldwide and is applied daily for a diverse spectrum of indications, from scheduled surgical procedures to acute organ failure. This state-of-the-art review provides an update on the basic physiology of respiratory mechanics, the working principles, and the main ventilatory settings, as well as the potential complications of mechanical ventilation. Specific ventilatory approaches in particular situations such as acute respiratory distress syndrome and chronic obstructive pulmonary disease are detailed along with protective ventilation in patients with normal lungs. We also highlight recent data on patient-ventilator dyssynchrony, humidified high-flow oxygen through nasal cannula, extracorporeal life support, and the weaning phase. Finally, we discuss the future of mechanical ventilation, addressing avenues for improvement. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  6. Housing and natural ventilation. Indoor climate, energy, reliability; Bolig og naturlig ventilation: indeklima energi driftssikkerhed

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, R.; Lauring, M. (eds.)

    2003-07-01

    The aim of this book is to show how natural ventilation can be used successfully in housing. Housing ventilation aims at balancing complex and often diametrically opposed demands. This book examines the complexity with different quantitative and qualitative approaches. In the first chapter, History, the Danish housing ventilation from 1850-2002 is examined. The requirements for natural ventilation have developed historically, based upon a spatial organisation with fresh air supply to the less polluted rooms and stack effect removal from the more polluted rooms. A series of important factors relating to a healthy indoor climate, energy savings and demands for functional stability have affected this development. In the second chapter, Models, a series of architectural models for natural ventilated large building types are analysed. There has for many years been much R and D activity aimed at using natural ventilation in large buildings. Much of the knowledge about the requirements for natural ventilation (spatial organisation, fresh air supply and stack effect removal) can therefore be used in the development of naturally ventilated housing. The third chapter, Principles, develops a set of principles for naturally ventilated housing by examining the requirements relating to spatial organisation, fresh air supply, and stack effect removal. By optimizing the architectural and technical design of a typical terraced house, the three aims for the successful use of natural ventilation in housing can be achieved; a very low energy consumption and environmental impact, a healthy indoor climate and a functionally stable ventilation system. The fourth chapter, Houses, presents architectural designs for a series of naturally ventilated terraced houses. The designs focus on the use of spatial organisation, fresh air supply and stack removal to optimize the natural ventilation. Architecture and technology are integrated in the design to achieve low energy consumption, a healthy

  7. Both high level pressure support ventilation and controlled mechanical ventilation induce diaphragm dysfunction and atrophy.

    Science.gov (United States)

    Hudson, Matthew B; Smuder, Ashley J; Nelson, W Bradley; Bruells, Christian S; Levine, Sanford; Powers, Scott K

    2012-04-01

    Previous workers have demonstrated that controlled mechanical ventilation results in diaphragm inactivity and elicits a rapid development of diaphragm weakness as a result of both contractile dysfunction and fiber atrophy. Limited data exist regarding the impact of pressure support ventilation, a commonly used mode of mechanical ventilation-that permits partial mechanical activity of the diaphragm-on diaphragm structure and function. We carried out the present study to test the hypothesis that high-level pressure support ventilation decreases the diaphragm pathology associated with CMV. Sprague-Dawley rats were randomly assigned to one of the following five groups:1) control (no mechanical ventilation); 2) 12 hrs of controlled mechanical ventilation (12CMV); 3) 18 hrs of controlled mechanical ventilation (18CMV); 4) 12 hrs of pressure support ventilation (12PSV); or 5) 18 hrs of pressure support ventilation (18PSV). We carried out the following measurements on diaphragm specimens: 4-hydroxynonenal-a marker of oxidative stress, active caspase-3 (casp-3), active calpain-1 (calp-1), fiber type cross-sectional area, and specific force (sp F). Compared with the control, both 12PSV and 18PSV promoted a significant decrement in diaphragmatic specific force production, but to a lesser degree than 12CMV and 18CMV. Furthermore, 12CMV, 18PSV, and 18CMV resulted in significant atrophy in all diaphragm fiber types as well as significant increases in a biomarker of oxidative stress (4-hydroxynonenal) and increased proteolytic activity (20S proteasome, calpain-1, and caspase-3). Furthermore, although no inspiratory effort occurs during controlled mechanical ventilation, it was observed that pressure support ventilation resulted in large decrement, approximately 96%, in inspiratory effort compared with spontaneously breathing animals. High levels of prolonged pressure support ventilation promote diaphragmatic atrophy and contractile dysfunction. Furthermore, similar to controlled

  8. An evaluation of ventilator reliability: a multivariate, failure time analysis of 5 common ventilator brands.

    Science.gov (United States)

    Blanch, P B

    2001-08-01

    Mechanical ventilator failures expose patients to unacceptable risks and are expensive. By identifying factors that correlate with the amount of time between consecutive ventilator failures, we might reduce patient risk, save money, and shed light on a number of important questions concerning whether reliability changes as a function of time. Investigate the correlation between several explanatory variables and the time between consecutive ventilator failures and address the following questions: (1) Are ventilators as safe and reliable following repairs as they were before failing? (2) Does reliability change significantly as a ventilator is used or ages? (3) Does a hospital's particular operating environment play a role in ventilator reliability? (4) Are ventilator service contracts worth the money? A retrospective review was conducted using repair and maintenance records from 2 hospitals: a 570-bed teaching hospital and a 410-bed local community hospital. Records were examined from a total of 66 individual ventilators, of 5 different brands, used between July 1, 1991, and January 3, 2001. The ventilators included 13 Tyco-Mallinckrodt Infant Star, 10 Bird VIP, 11 Bird 6400ST, 16 Bird 8400STi, and 16 Tyco-Mallinckrodt 7200ae. The dependent variable was the operating time between or before unexpected mechanical failures; this was determined by the difference between hours logged on the ventilator hour meter at the time of failure and that recorded when the study began, or when the ventilator was new. Thereafter (when applicable), the time before failure was the difference in hours at consecutive failures. Seven independent explanatory covariates were selected and analyzed as potential correlates with time between failures. Another independent variable, the site of ventilator use (community or teaching hospital), was also tested for significance. Data were analyzed using the Cox proportional hazard model, the multiple-groups survival statistic, and the Cox

  9. Mechanical ventilation during extracorporeal membrane oxygenation

    Science.gov (United States)

    2014-01-01

    The timing of extracorporeal membrane oxygenation (ECMO) initiation and its outcome in the management of respiratory and cardiac failure have received considerable attention, but very little attention has been given to mechanical ventilation during ECMO. Mechanical ventilation settings in non-ECMO studies have been shown to have an effect on survival and may also have contributed to a treatment effect in ECMO trials. Protective lung ventilation strategies established for non-ECMO-supported respiratory failure patients may not be optimal for more severe forms of respiratory failure requiring ECMO support. The influence of positive end-expiratory pressure on the reduction of the left ventricular compliance may be a matter of concern for patients receiving ECMO support for cardiac failure. The objectives of this review were to describe potential mechanisms for lung injury during ECMO for respiratory or cardiac failure, to assess the possible benefits from the use of ultra-protective lung ventilation strategies and to review published guidelines and expert opinions available on mechanical ventilation-specific management of patients requiring ECMO, including mode and ventilator settings. Articles were identified through a detailed search of PubMed, Ovid, Cochrane databases and Google Scholar. Additional references were retrieved from the selected studies. Growing evidence suggests that mechanical ventilation settings are important in ECMO patients to minimize further lung damage and improve outcomes. An ultra-protective ventilation strategy may be optimal for mechanical ventilation during ECMO for respiratory failure. The effects of airway pressure on right and left ventricular afterload should be considered during venoarterial ECMO support of cardiac failure. Future studies are needed to better understand the potential impact of invasive mechanical ventilation modes and settings on outcomes. PMID:24447458

  10. [Nursing outcomes for ineffective breathing patterns and impaired spontaneous ventilation in intensive care].

    Science.gov (United States)

    do Canto, Débora Francisco; Almeida, Miriam de Abreu

    2013-12-01

    This study aimed to validate the results of Nursing selected from the link NANDA-I-NOC (Nursing Outcomes Classification--NANDA--International) for diagnosis Ineffective Breathing Pattern and Impaired Spontaneous Ventilation in adult intensive care unit. This is a content validation study conducted in a university hospital in southern Brazil with 15 expert nurses with clinical experience and knowledge of the ratings. The instruments contained five-point Likert scales to rate the importance of each outcome (1st step) and indicator (Step 2) for the diagnoses studied. We calculated weighted averages for each outcome/indicator, considering) 1 = 0. 2 = 0.25, 3 = 0.50 4 = 0.75 and 5 = 1. The outcomes suggested by the NOC with averages above 0.8 were considered validated as well as the indicators. The results Respiratory State--airway permeability (Ineffective Breathing Patterns) and 11 indicators, and Response to mechanical ventilation: adult (Impaired Spontaneous Ventilation) with 26 indicators were validated.

  11. Electrical Impedance Tomography During Mechanical Ventilation.

    Science.gov (United States)

    Walsh, Brian K; Smallwood, Craig D

    2016-10-01

    Electrical impedance tomography (EIT) is a noninvasive, non-radiologic imaging modality that may be useful for the quantification of lung disorders and titration of mechanical ventilation. The principle of operation is based on changes in electrical conductivity that occur as a function of changes in lung volume during ventilation. EIT offers potentially important benefits over standard imaging modalities because the system is portable and non-radiologic and can be applied to patients for long periods of time. Rather than providing a technical dissection of the methods utilized to gather, compile, reconstruct, and display EIT images, the present article seeks to provide an overview of the clinical application of this technology as it relates to monitoring mechanical ventilation and providing decision support at the bedside. EIT has been shown to be useful in the detection of pneumothoraces, quantification of pulmonary edema and comparison of distribution of ventilation between different modes of ventilation and may offer superior individual titration of PEEP and other ventilator parameters compared with existing approaches. Although application of EIT is still primarily done within a research context, it may prove to be a useful bedside tool in the future. However, head-to-head comparisons with existing methods of mechanical ventilation titration in humans need to be conducted before its application in general ICUs can be recommended. Copyright © 2016 by Daedalus Enterprises.

  12. Infiltration as Ventilation: Weather-Induced Dilution

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Turner, William J.N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-06-01

    The purpose of outdoor air ventilation is to dilute or remove indoor contaminants to which occupants are exposed. It can be provided by mechanical or natural means. In most homes, especially older homes, weather-driven infiltration provides the dominant fraction of the total ventilation. As we seek to provide good indoor air quality at minimum energy cost, it is important to neither over-ventilate nor under-ventilate. Thus, it becomes critically important to evaluate correctly the contribution infiltration makes to the total outdoor air ventilation rate. Because weather-driven infiltration is dependent on building air leakage and weather-induced pressure differences, a given amount of air leakage will provide different amounts of infiltration. Varying rates of infiltration will provide different levels of contaminant dilution and hence effective ventilation. This paper derives these interactions and then calculates the impact of weather-driven infiltration for different climates. A new “N-factor” is introduced to provide a convenient method for calculating the ventilation contribution of infiltration for over 1,000 locations across North America. The results of this work could be used in indoor air quality standards (specifically ASHRAE 62.2) to account for the contribution of weather-driven infiltration towards the dilution of indoor pollutants.

  13. Significant Improvements in Pyranometer Nighttime Offsets Using High-Flow DC Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Kutchenreiter, Mark; Michalski, J.J.; Long, C.N.; Habte, Aron

    2017-05-22

    Accurate solar radiation measurements using pyranometers are required to understand radiative impacts on the Earth's energy budget, solar energy production, and to validate radiative transfer models. Ventilators of pyranometers, which are used to keep the domes clean and dry, also affect instrument thermal offset accuracy. This poster presents a high-level overview of the ventilators for single-black-detector pyranometers and black-and-white pyranometers. For single-black-detector pyranometers with ventilators, high-flow-rate (50-CFM and higher), 12-V DC fans lower the offsets, lower the scatter, and improve the predictability of nighttime offsets compared to lower-flow-rate (35-CFM), 120-V AC fans operated in the same type of environmental setup. Black-and-white pyranometers, which are used to measure diffuse horizontal irradiance, sometimes show minor improvement with DC fan ventilation, but their offsets are always small, usually no more than 1 W/m2, whether AC- or DC-ventilated.

  14. Variation in Definition of Prolonged Mechanical Ventilation.

    Science.gov (United States)

    Rose, Louise; McGinlay, Michael; Amin, Reshma; Burns, Karen Ea; Connolly, Bronwen; Hart, Nicholas; Jouvet, Philippe; Katz, Sherri; Leasa, David; Mawdsley, Cathy; McAuley, Danny F; Schultz, Marcus J; Blackwood, Bronagh

    2017-10-01

    Consistency of definitional criteria for terminology applied to describe subject cohorts receiving mechanical ventilation within ICU and post-acute care settings is important for understanding prevalence, risk stratification, effectiveness of interventions, and projections for resource allocation. Our objective was to quantify the application and definition of terms for prolonged mechanical ventilation. We conducted a scoping review of studies (all designs except single-case study) reporting a study population (adult and pediatric) using the term prolonged mechanical ventilation or a synonym. We screened 5,331 references, reviewed 539 full-text references, and excluded 120. Of the 419 studies (representing 38 countries) meeting inclusion criteria, 297 (71%) reported data on a heterogeneous subject cohort, and 66 (16%) included surgical subjects only (46 of those 66, 70% cardiac surgery). Other studies described COPD (16, 4%), trauma (22, 5%), neuromuscular (17, 4%), and sepsis (1, 0.2%) cohorts. A total of 741 terms were used to refer to the 419 study cohorts. The most common terms were: prolonged mechanical ventilation (253, 60%), admission to specialized unit (107, 26%), and long-term mechanical ventilation (79, 19%). Some authors (282, 67%) defined their cohorts based on duration of mechanical ventilation, with 154 studies (55%) using this as the sole criterion. We identified 37 different durations of ventilation ranging from 5 h to 1 y, with > 21 d being the most common (28 of 282, 7%). For studies describing a surgical cohort, minimum ventilation duration required for inclusion was ≥ 24 h for 20 of 66 studies (30%). More than half of all studies (237, 57%) did not provide a reason/rationale for definitional criteria used, with only 28 studies (7%) referring to a consensus definition. We conclude that substantial variation exists in the terminology and definitional criteria for cohorts of subjects receiving prolonged mechanical ventilation. Standardization of

  15. Real-time evaluation of ventilation filter-bank systems.

    Science.gov (United States)

    Moyer, Ernest S; Commodore, Michael A; Hayes, Jeffrey L; Fotta, Steven A; Berardinelli, Stephen P

    2007-01-01

    This study evaluated two government facility ventilation systems. One was a metropolitan government office complex with a recirculation system where outside air was the makeup air; the other was a NIOSH facility that used 100% outside air with no recirculation. The methodology employed was a modified American Society of Agricultural Engineers standard (S525) for testing total enclosure filtration efficiency, in agricultural tractor cabs, with optical particle counters (OPC). The low-efficiency bag filters were tested when new and after being in the ventilation system for 3 months. The replacement medium-efficiency filters were evaluated for 6 months (the manufacturer's suggested change-out schedule). These eight-chamber, medium-efficiency filters had an increased filter surface area that resulted in increased airflow through the system. Unfortunately, these filters contained electrostatic filter media and lost filtration efficiency rapidly, which was subsequently confirmed in a 30-day study conducted to determine an appropriate change-out schedule for the eight-chamber bag filters. The study determined that less than 6 months' use was justified due to the reduced efficiency of the electrostatic filter media. The NIOSH facility's air handler #8 (100% outside air unit) was upgraded from electrostatic bag filters, which had a suggested 9-month change-out schedule, to V Bank mechanical, wet-laid, glass fiber filters. The results of a 3-year evaluation showed that the V Bank filters had better filter efficiency after 3 years of service than the electrostatic filters had at 9 months. Both studies employed matched OPC instruments to reduce instrument-to-instrument bias. The methodology is adaptable to monitoring the total efficiency of most air filtration systems, and results can help make decisions about upgrading filter performance.

  16. Preoperational test report, primary ventilation condensate system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-01-29

    Preoperational test report for Primary Ventilation Condensate System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides a collection point for condensate generated by the W-030 primary vent offgas cooling system serving tanks AYIOI, AY102, AZIOI, AZI02. The system is located inside a shielded ventilation equipment cell and consists of a condensate seal pot, sampling features, a drain line to existing Catch Tank 241-AZ-151, and a cell sump jet pump. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  17. Multilevel Ventilation: Theory and Simplified Mathematical Model

    Directory of Open Access Journals (Sweden)

    P. Torok

    2008-01-01

    Full Text Available Considering the issues of artificial ventilation (AV in non-homogenous pathological lung processes (acute lung injury, acute respiratory distress syndrome, pneumonia, etc., the authors created a mathematical model of multicompartment non-homogenous injured lungs that were ventilated by a new mode of AV, the so-called three-level ventilation. Multilevel ventilation was defined a type (modification of ALV whose basic ventilation level was produced by the modes CMV, PCV or PS (ASB and add-on level, and the so-called background ventilation was generated by the levels of PEEP and high PEEP (PEEPh with varying frequency and duration. Multi-level ventilation on 3 pressure levels was realized by the mathematical model as a combination of pressure-controlled ventilation (PCV and two levels of PEEP and PEEPh. The objective was to prove that in cases of considerably non-homogenous gas distribution in acute pathological disorders of lungs, gas entry into the so-called slow bronchoalveolar compartments could be improved by multilevel AV, without substabtially changing the volume of so-called fast compartments. Material and Method. Multi-level ventilation at 3 pressure levels was realized by the mathematical model as a combination of PCV and two levels of PEEP and PEEPh. Results. By comparing the single-level AV in the PCV mode with the so-called three-level ventilation defined as a combination of PCV+PEEPh/PEEP, the authors have discovered that the loading of slow compartments in the model was considerably improved by 50—60% as compared with the baseline values. In absolute terms, this difference was as many as 2—10 times of the volume. Conclusion. The mathematical model may demonstrate that the application of the so-called three-level AV causes considerable changes in gas distribution in the lung parenchyma disordered by a non-homogenous pathological process. The authors state that the proposed mathematical model requires clinical verification in order

  18. Secretion management in the mechanically ventilated patient.

    Science.gov (United States)

    Branson, Richard D

    2007-10-01

    Secretion management in the mechanically ventilated patient includes routine methods for maintaining mucociliary function, as well as techniques for secretion removal. Humidification, mobilization of the patient, and airway suctioning are all routine procedures for managing secretions in the ventilated patient. Early ambulation of the post-surgical patient and routine turning of the ventilated patient are common secretion-management techniques that have little supporting evidence of efficacy. Humidification is a standard of care and a requisite for secretion management. Both active and passive humidification can be used. The humidifier selected and the level of humidification required depend on the patient's condition and the expected duration of intubation. In patients with thick, copious secretions, heated humidification is superior to a heat and moisture exchanger. Airway suctioning is the most important secretion removal technique. Open-circuit and closed-circuit suctioning have similar efficacy. Instilling saline prior to suctioning, to thin the secretions or stimulate a cough, is not supported by the literature. Adequate humidification and as-needed suctioning are the foundation of secretion management in the mechanically ventilated patient. Intermittent therapy for secretion removal includes techniques either to simulate a cough, to mechanically loosen secretions, or both. Patient positioning for secretion drainage is also widely used. Percussion and postural drainage have been widely employed for mechanically ventilated patients but have not been shown to reduce ventilator-associated pneumonia or atelectasis. Manual hyperinflation and insufflation-exsufflation, which attempt to improve secretion removal by simulating a cough, have been described in mechanically ventilated patients, but neither has been studied sufficiently to support routine use. Continuous lateral rotation with a specialized bed reduces atelectasis in some patients, but has not been shown

  19. Weaning newborn infants from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Paolo Biban

    2013-06-01

    Full Text Available Invasive mechanical ventilation is a life-saving procedure which is largely used in neonatal intensive care units, particularly in very premature newborn infants. However, this essential treatment may increase mortality and cause substantial morbidity, including lung or airway injuries, unplanned extubations, adverse hemodynamic effects, analgosedative dependency and severe infectious complications, such as ventilator-associated pneumonia. Therefore, limiting the duration of airway intubation and mechanical ventilator support is crucial for the neonatologist, who should aim to a shorter process of discontinuing mechanical ventilation as well as an earlier appreciation of readiness for spontaneous breathing trials. Unfortunately, there is scarce information about the best ways to perform an effective weaning process in infants undergoing mechanical ventilation, thus in most cases the weaning course is still based upon the individual judgment of the attending clinician. Nonetheless, some evidence indicate that volume targeted ventilation modes are more effective in reducing the duration of mechanical ventilation than traditional pressure limited ventilation modes, particularly in very preterm babies. Weaning and extubation directly from high frequency ventilation could be another option, even though its effectiveness, when compared to switching and subsequent weaning and extubating from conventional ventilation, is yet to be adequately investigated. Some data suggest the use of weaning protocols could reduce the weaning time and duration of mechanical ventilation, but better designed prospective studies are still needed to confirm these preliminary observations. Finally, the implementation of short spontaneous breathing tests in preterm infants has been shown to be beneficial in some centres, favoring an earlier extubation at higher ventilatory settings compared with historical controls, without worsening the extubation failure rate. Further

  20. Special Considerations in Neonatal Mechanical Ventilation.

    Science.gov (United States)

    Dalgleish, Stacey; Kostecky, Linda; Charania, Irina

    2016-12-01

    Care of infants supported with mechanical ventilation is complex, time intensive, and requires constant vigilance by an expertly prepared health care team. Current evidence must guide nursing practice regarding ventilated neonates. This article highlights the importance of common language to establish a shared mental model and enhance clear communication among the interprofessional team. Knowledge regarding the underpinnings of an open lung strategy and the interplay between the pathophysiology and individual infant's response to a specific ventilator strategy is most likely to result in a positive clinical outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Do new anesthesia ventilators deliver small tidal volumes accurately during volume-controlled ventilation?

    Science.gov (United States)

    Bachiller, Patricia R; McDonough, Joseph M; Feldman, Jeffrey M

    2008-05-01

    During mechanical ventilation of infants and neonates, small changes in tidal volume may lead to hypo- or hyperventilation, barotrauma, or volutrauma. Partly because breathing circuit compliance and fresh gas flow affect tidal volume delivery by traditional anesthesia ventilators in volume-controlled ventilation (VCV) mode, pressure-controlled ventilation (PCV) using a circle breathing system has become a common approach to minimizing the risk of mechanical ventilation for small patients, although delivered tidal volume is not assured during PCV. A new generation of anesthesia machine ventilators addresses the problems of VCV by adjusting for fresh gas flow and for the compliance of the breathing circuit. In this study, we evaluated the accuracy of new anesthesia ventilators to deliver small tidal volumes. Four anesthesia ventilator systems were evaluated to determine the accuracy of volume delivery to the airway during VCV at tidal volume settings of 100, 200, and 500 mL under different conditions of breathing circuit compliance (fully extended and fully contracted circuits) and lung compliance. A mechanical test lung (adult and infant) was used to simulate lung compliances ranging from 0.0025 to 0.03 L/cm H(2)O. Volumes and pressures were measured using a calibrated screen pneumotachograph and custom software. We tested the Smartvent 7900, Avance, and Aisys anesthesia ventilator systems (GE Healthcare, Madison, WI) and the Apollo anesthesia ventilator (Draeger Medical, Telford, PA). The Smartvent 7900 and Avance ventilators use inspiratory flow sensors to control the volume delivered, whereas the Aisys and Apollo ventilators compensate for the compliance of the circuit. We found that the anesthesia ventilators that use compliance compensation (Aisys and Apollo) accurately delivered both large and small tidal volumes to the airway of the test lung under conditions of normal and low lung compliance during VCV (ranging from 95.5% to 106.2% of the set tidal volume

  2. 33 CFR 183.620 - Natural ventilation system.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Natural ventilation system. 183... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.620 Natural ventilation system. (a) Except for compartments open to the atmosphere, a natural ventilation system that meets the...

  3. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b) The...

  4. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts for...

  5. [Prognostic criteria of the premature infants weaning from mechanical ventilation during trigger ventilation].

    Science.gov (United States)

    Grebennikov, V A; Kriakvina, O A; Bolunova, E S; Degtiareva, M V

    2013-01-01

    Modern mechanical ventilation modes do not prevent ventilator-associated lung injury therefore respiratory cessation must be stopped as soon as possible. However extubation recommendations absence makes difficulties in process of weaning the infants from the mechanical ventilation. To assess the prognostic criteria of the extubating and weaning from mechanical ventilation in premature infants during trigger ventilation (PSV/PSV + VG). 66 Pediatric patients were divided into two groups during the period of weaning from mechanical ventilation: PSV + PG ventilation mode was used in the group 1 (n = 33), and PSV in the group 2 (n = 33). Basic characteristics were same in both groups: gestational age 31.1 +/- 2.5 weeks, mass of body 1586.2 +/- 356.8 grams. Extubation was successful if reintubation was not needed during 48 hrs. 90% of successful extubations were done when the compliance was over 1.1 ml mbar(-1). Compliance decrease under 0.75 ml mbar(-1) was an adverse prognostic criterion of the weaning from mechanical ventilation and extubation. Index breathing rate/breathing volume (RVR) can be used as general criterion of the weaning from mechanical ventilation. Progressive RVR increase to 8 is an adverse prognostic criterion of PSV/ PSV + VG mode use during the period of weaning from mechanical ventilation. Parameters of mechanical ventilation which maintain acceptable gas composition of blood and SpO2 mast be considered before extubation. Positive dynamics and stabilization of compliance and resistance are essential criteria of the successful weaning from mechanical ventilation and extubation. RVR can be used as objective criterion of an extubation.

  6. Neurally adjusted ventilatory assist improves patient–ventilator interaction in infants as compared with conventional ventilation.

    Science.gov (United States)

    Bordessoule, Alice; Emeriaud, Guillaume; Morneau, Sylvain; Jouvet, Philippe; Beck, Jennifer

    2012-08-01

    Neurally adjusted ventilatory assist (NAVA) is a mode of ventilation controlled by the electrical activity of the diaphragm (Edi). The aim was to evaluate patient-ventilator interaction in infants during NAVA as compared with conventional ventilation. Infants were successively ventilated with NAVA, pressure control ventilation (PCV), and pressure support ventilation (PSV). Edi and ventilator pressure (Pvent) waveforms were compared and their variability was assessed by coefficients of variation. Ten patients (mean age 4.3 ± 2.4 mo and weight 5.9 ± 2.2 kg) were studied. In PCV and PSV, 4 ± 4.6% and 6.5 ± 7.7% of the neural efforts failed to trigger the ventilator. This did not occur during NAVA. Trigger delays were shorter with NAVA as compared with PCV and PSV (93 ± 20 ms vs. 193 ± 87 ms and 135 ± 29 ms). During PCV and PSV, the ventilator cycled off before the end of neural inspiration in 12 ± 13% and 21 ± 19% of the breaths (0 ± 0% during NAVA). During PCV and PSV, 24 ± 11% and 25 ± 9% of the neural breath cycle was asynchronous with the ventilator as compared with 11 ± 3% with NAVA. A large variability was observed for Edi in all modes, which was transmitted into Pvent during NAVA (coefficient of variation: 24 ± 8%) and not in PCV (coefficient of variation 2 ± 1%) or PSV (2 ± 2%). NAVA improves patient-ventilator interaction and delivers adequate ventilation with variable pressure in infants.

  7. Energy diagnosis of industrial ventilation systems; Diagnostic energetique des installations de ventilation industrielle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-11-01

    Industrial ventilation systems are numerous and represent an important source of potential energy saving. This book shades light on the principles of ventilation systems used in companies and on the investigation methods to be implemented for an energy diagnosis of these systems. It proposes some solutions for the improvement of existing ventilation systems and some suggestions for the formulation and presentation of recommendations. (J.S.)

  8. Using a Ventilation Controller to Optimize Residential Passive Ventilation For Energy and Indoor Air Quality

    Energy Technology Data Exchange (ETDEWEB)

    Turner, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    One way to reduce the energy impact of providing residential ventilation is to use passive and hybrid systems. However, these passive and hybrid (sometimes called mixed-mode) systems must still meet chronic and acute health standards for ventilation. This study uses a computer simulation approach to examine the energy and indoor air quality (IAQ) implications of passive and hybrid ventilation systems, in 16 California climate zones. Both uncontrolled and flow controlled passive stacks are assessed. A new hybrid ventilation system is outlined that uses an intelligent ventilation controller to minimise energy use, while ensuring chronic and acute IAQ standards are met. ASHRAE Standard 62.2-2010 – the United States standard for residential ventilation - is used as the chronic standard, and exposure limits for PM2.5, formaldehyde and NO2 are used as the acute standards.The results show that controlled passive ventilation and hybrid ventilation can be used in homes to provide equivalent IAQ to continuous mechanical ventilation, for less use of energy.

  9. Comfort parameters - Ventilation of a subway wagon

    Science.gov (United States)

    Petr, Pavlíček; Ladislav, Tříska

    2017-09-01

    Research and development of a ventilation system is being carried out as a part of project TA04030774 of the Technology Agency of the Czech Republic. Name of the project is "Research and Development of Mass-optimized Components for Rail Vehicles". Problems being solved are development and testing of a new concept for ventilation systems for public transport vehicles. The main improvements should be a reduction of the mass of the whole system, easy installation and reduction of the noise of the ventilation system. This article is focused on the comfort parameters in a subway wagon (measurement and evaluation carried out on a function sample in accordance with the regulations). The input to the project is a ventilator hybrid casing for a subway wagon, which was manufactured and tested during the Ministry of Industry and Trade project TIP FR-TI3/449.

  10. Adaptive Intelligent Ventilation Noise Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA needs for quiet crew volumes in a space habitat, Physical Optics Corporation (POC) proposes to develop a new Adaptive Intelligent Ventilation Noise...

  11. Adaptive Intelligent Ventilation Noise Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA need for quiet on-orbit crew quarters (CQ), Physical Optics Corporation (POC) proposes to develop a new Adaptive Intelligent Ventilation Noise...

  12. Design of Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The effectiveness of natural ventilation, i.e. its ability to ensure indoor air quality and passive cooling in a building, depends greatly on the design process. Mechanical ventilation systems can be designed separately from the design of the building in which they are installed. They can also...... be installed in existing buildings after a few modifications. In contrast, ventilation systems using only natural forces such as wind and thermal buoyancy need to be designed together with the building, since the building itself and its components are the elements that can reduce or increase air movement...... as well as influence the air content (dust, pollution etc.). Architects and engineers need to acquire qualitative and quantitative information about the interactions between building characteristics and natural ventilation in order to design buildings and systems consistent with a passive low...

  13. Process control migration towards LHC ventilation functionality

    CERN Document Server

    Blanc, D

    2003-01-01

    The adaptation of the ventilation systems as well as the integration of equipment to fit with the new LHC ventilation requirements lead us to consider a global re-engineering of the existing control system. This, decade old process control structure is composed of elements which are mixed between industrial and home made devices. The proposed modifications are made in order to upgrade the present control system and to provide efficient and well adapted control architecture to integrate the LHC ventilation equipment of the injection tunnels. Moreover, we need a plan for the next fifteen years of the LHC life cycle. The document is to present the situation of the present control system of the LEP ventilation process and to propose a plan for the migration of the control architecture. This is done considering the fact that elements of the present control infrastructure could no longer be supported from 2003 and major components must be removed from the CERN communication infrastructure.

  14. Modelling of Natural and Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    as well as influence the air content (dust, pollution etc.). Architects and engineers need to acquire qualitative and quantitative information about the interactions between building characteristics and natural ventilation in order to design buildings and systems consistent with a passive low......The effectiveness of natural ventilation, i.e. its ability to ensure indoor air quality and passive cooling in a building, depends greatly on the design process. Mechanical ventilation systems can be designed separately from the design of the building in which they are installed. They can also...... be installed in existing buildings after a few modifications. In contrast, ventilation systems using only natural forces such as wind and thermal buoyancy need to be designed together with the building, since the building itself and its components are the elements that can reduce or increase air movement...

  15. Mechanical ventilation strategies for the surgical patient

    NARCIS (Netherlands)

    Schultz, Marcus J.; Abreu, Marcelo Gama de; Pelosi, Paolo

    2015-01-01

    Purpose of review To summarize clinical evidence for intraoperative ventilation settings, which could protect against postoperative pulmonary complications (PPCs) in surgical patients with uninjured lungs. Recent findings There is convincing evidence for protection against PPCs by low tidal volumes:

  16. 46 CFR 111.15-10 - Ventilation.

    Science.gov (United States)

    2010-10-01

    .... (3) Each blower must have a non-sparking fan. (4) The power ventilation system must be interlocked... vertical; and (iv) That has no appliances, such as flame arresters, that impede free passage of air or gas...

  17. Comparison of Airway Pressure Release Ventilation to Conventional Mechanical Ventilation in the Early Management of Smoke Inhalation Injury in Swine

    Science.gov (United States)

    2011-01-01

    Comparison of airway pressure release ventilation to conventional mechanical ventilation in the early management of smoke inhalation injury in swine...Acute respiratory distress syndrome (ARDS) is a complication of smoke inha- lation injury, with an incidence as high as 54% in mechanically ventilated ... mechanical ventilation on oxygenation in a porcine model of acute respiratory distress syndrome induced by wood smoke inhalation. Design: Prospective

  18. Evaluating Ventilation Systems for Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Arena, Lois [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2013-02-01

    In an effort to improve housing options near Las Vegas, Nevada, the Clark County Community Resources Division (CCCRD) performs substantial renovations to foreclosed homes. After dramatic energy, aesthetic, and health and safety improvements are made, homes are rented or sold to qualified residents. This report describes the evaluation and selection of ventilation systems for these homes, including key considerations when selecting an ideal system. The report then describes CCCRD’s decision process with respect to ventilation.

  19. Computational Fluid Dynamics in Ventilation Design

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    2008-01-01

    . The guidebook has, for example, chapters that are very important for CFD quality control in general, and for the quality control of ventilation related problems in particular. A large number of CFD predictions are made nowadays, and it is often difficult to judge the quality level of these predictions....... The guidebook introduces rules for good quality prediction work, and it is the purpose of the guidebook to improve the technical level of CFD work in ventilation....

  20. Sensor-based demand controlled ventilation

    Energy Technology Data Exchange (ETDEWEB)

    De Almeida, A.T. [Universidade de Coimbra (Portugal). Dep. Eng. Electrotecnica; Fisk, W.J. [Lawrence Berkeley National Lab., CA (United States)

    1997-07-01

    In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation rates are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.

  1. Solar ventilation for vehicles. Solarstandentlueftung fuer Kraftfahrzeuge

    Energy Technology Data Exchange (ETDEWEB)

    Watzlawick, R. (Webasto Karosseriesysteme GmbH, Stockdorf (Germany)); Ganz, T. (Webasto Karosseriesysteme GmbH, Stockdorf (Germany)); Adelmann, P. (STECA GmbH, Memmingen (Germany))

    1993-01-01

    Considerable improvement in comfort and further price reductions by a simple process for including the solar cells in a sliding roof and the solar module itself make solar ventilation an attractive component in vehicle air conditioning. With regard to increasing shortages of raw materials and the trend towards engines with optimized consumption, solar ventilation can make a considerable contribution to environmentally-friendly air conditioning in the vehicles. (orig.)

  2. Efficacy of Conventional and High-Frequency Ventilation at Altitude

    Science.gov (United States)

    1988-12-01

    evacuation; Mechanical ventilation ;--andL If.’jJI t’ 06 I 12 i ~High-Frequency ventilation ’& ~.~.- 19 ABSTRACT (Continue on reverse If neesry and identify by...The inspired gas and the subsequent rate of appearance of these gases in arterial blood were monitored. With conventional mechanical ventilation (CMV...AND HIGH-FREQUENCY VENTILATION AT ALTITUDE INTRODUCTION The logistics of aeromedical evacuation of patients requiring mechanical ventilation is

  3. Non-invasive ventilation for cystic fibrosis.

    Science.gov (United States)

    Moran, Fidelma; Bradley, Judy M; Piper, Amanda J

    2017-02-20

    Non-invasive ventilation may be a means to temporarily reverse or slow the progression of respiratory failure in cystic fibrosis by providing ventilatory support and avoiding tracheal intubation. Using non-invasive ventilation, in the appropriate situation or individuals, can improve lung mechanics through increasing airflow and gas exchange and decreasing the work of breathing. Non-invasive ventilation thus acts as an external respiratory muscle. This is an update of a previously published review. To compare the effect of non-invasive ventilation versus no non-invasive ventilation in people with cystic fibrosis for airway clearance, during sleep and during exercise. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings. We searched the reference lists of each trial for additional publications possibly containing other trials.Most recent search: 08 August 2016. Randomised controlled trials comparing a form of pressure preset or volume preset non-invasive ventilation to no non-invasive ventilation used for airway clearance or during sleep or exercise in people with acute or chronic respiratory failure in cystic fibrosis. Three reviewers independently assessed trials for inclusion criteria and methodological quality, and extracted data. Ten trials met the inclusion criteria with a total of 191 participants. Seven trials evaluated single treatment sessions, one evaluated a two-week intervention, one evaluated a six-week intervention and one a three-month intervention. It is only possible to blind trials of airway clearance and overnight ventilatory support to the outcome assessors. In most of the trials we judged there was an unclear risk of bias with regards to blinding due to inadequate descriptions. The six-week trial was the only one judged to have a low risk of bias for all

  4. 3 Level Ventilation: the First Clinical Experience

    Directory of Open Access Journals (Sweden)

    P. Torok

    2008-01-01

    Full Text Available Considering the issues of artificial ventilation (AV in non-homogenous pathological lung processes (acute lung injury (ALI, acute respiratory distress syndrome (ARDS, pneumonia, etc., the authors applied the three-level lung ventilation to a group of 12 patients with non-homogenous lung injury. Three-level ventilation was defined as a type (modification of AV whose basic ventilation level was produced by the modes CMV, PCV or PS (ASB and add-on level, the so-called background ventilation was generated by two levels of PEEP. PEEP (constant and PEEPh (PEEP high with varying frequency and duration of transition between the individual levels of PEEP. Objective: to elucidate whether in cases of considerably non-homogenous gas distribution in acute pathological disorders, three-level ventilation (3LV can correct gas distribution into the so-called slow bronchoalveolar compartments, by decreasing the volume load of the so-called fast compartments and to improve lung gas exchange, by following the principles of safe ventilation. Results. 3LV was applied to 12 patients with severe non-homogenous lung injury/disorder (atypic pneumonia and ARDS/ALI and low-success PCV ventilation after recruitment manoeuvre (PaO2 (kPA /FiO2 = 5—6. There were pronounced positive changes in pulmonary gas exchange within 1—4 hours after initiation of 3LV at a fPCV of 26±4 breaths/min-1 and PEEPh at a fPEEPH of 7±2 breaths/min-1 with a minute ventilation of 12±4 l/min. 3LV reduced a intrapulmonary shunt fraction 50±5 to 30±5%, increased CO2 elimination, with PaCO2 falling to the values below 6±0.3 kPa, and PaO2 to 7.5±1.2 kPa, with FiO2 being decreased to 0.8—0.4. Lung recruitment also improved gas exchange: with PEEP=1.2±0.4 kPa, static tho-racopulmonary compliance (Cst elevated from 0.18±0.02 l/kPa to 0.3±0.02 l/kPa and then to 0.38±0.05 l/kPa. Airways resistance (Raw decreased by more than 30%. Improved lung aeration was also estimated as a manifestation of

  5. Daily Goals Formulation and Enhanced Visualization of Mechanical Ventilation Variance Improves Mechanical Ventilation Score.

    Science.gov (United States)

    Walsh, Brian K; Smallwood, Craig; Rettig, Jordan; Kacmarek, Robert M; Thompson, John; Arnold, John H

    2017-03-01

    The systematic implementation of evidence-based practice through the use of guidelines, checklists, and protocols mitigates the risks associated with mechanical ventilation, yet variation in practice remains prevalent. Recent advances in software and hardware have allowed for the development and deployment of an enhanced visualization tool that identifies mechanical ventilation goal variance. Our aim was to assess the utility of daily goal establishment and a computer-aided visualization of variance. This study was composed of 3 phases: a retrospective observational phase (baseline) followed by 2 prospective sequential interventions. Phase I intervention comprised daily goal establishment of mechanical ventilation. Phase II intervention was the setting and monitoring of daily goals of mechanical ventilation with a web-based data visualization system (T3). A single score of mechanical ventilation was developed to evaluate the outcome. The baseline phase evaluated 130 subjects, phase I enrolled 31 subjects, and phase II enrolled 36 subjects. There were no differences in demographic characteristics between cohorts. A total of 171 verbalizations of goals of mechanical ventilation were completed in phase I. The use of T3 increased by 87% from phase I. Mechanical ventilation score improved by 8.4% in phase I and 11.3% in phase II from baseline ( P = .032). The largest effect was in the low risk V T category, with a 40.3% improvement from baseline in phase I, which was maintained at 39% improvement from baseline in phase II ( P = .01). mechanical ventilation score was 9% higher on average in those who survived. Daily goal formation and computer-enhanced visualization of mechanical ventilation variance were associated with an improvement in goal attainment by evidence of an improved mechanical ventilation score. Further research is needed to determine whether improvements in mechanical ventilation score through a targeted, process-oriented intervention will lead to

  6. Partial liquid ventilation improves lung function in ventilation-induced lung injury

    NARCIS (Netherlands)

    G.F. Vazquez de Anda; R.A. Lachmann; S.J.C. Verbrugge (Serge); D.A.M.P.J. Gommers (Diederik); J.J. Haitsma (Jack); B.F. Lachmann (Burkhard)

    2001-01-01

    textabstractDisturbances in lung function and lung mechanics are present after ventilation with high peak inspiratory pressures (PIP) and low levels of positive end-expiratory pressure (PEEP). Therefore, the authors investigated whether partial liquid ventilation can re-establish

  7. Recommendations for mechanical ventilation of critically ill children from the Paediatric Mechanical Ventilation Consensus Conference (PEMVECC).

    Science.gov (United States)

    Kneyber, Martin C J; de Luca, Daniele; Calderini, Edoardo; Jarreau, Pierre-Henri; Javouhey, Etienne; Lopez-Herce, Jesus; Hammer, Jürg; Macrae, Duncan; Markhorst, Dick G; Medina, Alberto; Pons-Odena, Marti; Racca, Fabrizio; Wolf, Gerhard; Biban, Paolo; Brierley, Joe; Rimensberger, Peter C

    2017-12-01

    Much of the common practice in paediatric mechanical ventilation is based on personal experiences and what paediatric critical care practitioners have adopted from adult and neonatal experience. This presents a barrier to planning and interpretation of clinical trials on the use of specific and targeted interventions. We aim to establish a European consensus guideline on mechanical ventilation of critically children. The European Society for Paediatric and Neonatal Intensive Care initiated a consensus conference of international European experts in paediatric mechanical ventilation to provide recommendations using the Research and Development/University of California, Los Angeles, appropriateness method. An electronic literature search in PubMed and EMBASE was performed using a combination of medical subject heading terms and text words related to mechanical ventilation and disease-specific terms. The Paediatric Mechanical Ventilation Consensus Conference (PEMVECC) consisted of a panel of 15 experts who developed and voted on 152 recommendations related to the following topics: (1) general recommendations, (2) monitoring, (3) targets of oxygenation and ventilation, (4) supportive measures, (5) weaning and extubation readiness, (6) normal lungs, (7) obstructive diseases, (8) restrictive diseases, (9) mixed diseases, (10) chronically ventilated patients, (11) cardiac patients and (12) lung hypoplasia syndromes. There were 142 (93.4%) recommendations with "strong agreement". The final iteration of the recommendations had none with equipoise or disagreement. These recommendations should help to harmonise the approach to paediatric mechanical ventilation and can be proposed as a standard-of-care applicable in daily clinical practice and clinical research.

  8. Comparative performance assessment of a non-ventilated and ventilated BIPV rooftop configurations in the Netherlands

    NARCIS (Netherlands)

    Ritzen, M.J.; Vroon, Z.A.E.P.; Rovers, R.; Geurts, C.P.W.

    2017-01-01

    Backside ventilation is one of the most common passive cooling methods of PV modules in the built environment, but might be under constraint when integrating PV in the building envelope. To investigate the short and long term effect of backside ventilation on Building Integrated PV (BIPV)

  9. Mechanical ventilation in emergency departments: Non invasive or invasive mechanical ventilation. Where is the answer?

    OpenAIRE

    Esquinas Rodriguez Antonio M; Cosentini Roberto; Papadakos Peter J

    2012-01-01

    The Emergency Department length of stay for patients requiring mechanical ventilation paper in this issue is very illustrative of many variables that still confound the way we treat patients that may not require endotracheal intubation (ETI) but may benefit from non-invasive mechanical ventilation (NIV) [1].

  10. Recovery Ventilation and Oxygen Debt-A Mathematical Model for the Prediction of Recovery Ventilation

    OpenAIRE

    G. P. Dimri; Arora, B. S.

    1982-01-01

    A Mathematical model has been evolved for the estimation of recovery ventilation following an exercise. The model has been used to estimate recovery ventilation in moderate to heavy exercise for a period of 32 minutes. The model gives satisfactory predictions for persons of different age groups and under different environment conditions thus establishing its universal applicability.

  11. Characteristics of rain penetration through a gravity ventilator used for natural ventilation.

    Science.gov (United States)

    Kim, Taehyeung; Lee, Dong Ho; Ahn, Kwangseog; Ha, Hyunchul; Park, Heechang; Piao, Cheng Xu; Li, Xiaoyu; Seo, Jeoungyoon

    2008-01-01

    Gravity ventilators rely simply on air buoyancy to extract air and are widely used to exhaust air contaminants and heat from workplaces using minimal energy. They are designed to maximize the exhaust flow rate, but the rain penetration sometimes causes malfunctioning. In this study, the characteristics of rain penetration through a ventilator were examined as a preliminary study to develop a ventilator with the maximum exhaust capacity while minimizing rain penetration. A model ventilator was built and exposed to artificial rain and wind. The paths, intensities and amounts of penetration through the ventilator were observed and measured in qualitative and quantitative fashions. In the first phase, the pathways and intensities of rain penetration were visually observed. In the second phase, the amounts of rain penetration were quantitatively measured under the different configurations of ventilator components that were installed based on the information obtained in the first-phase experiment. The effects of wind speed, grill direction, rain drainage width, outer wall height, neck height and leaning angle of the outer wall from the vertical position were analyzed. Wind speed significantly affected rain penetration. Under the low crosswind conditions, the rain penetration intensities were under the limit of detection. Under the high crosswind conditions, grill direction and neck height were the most significant factors in reducing rain penetration. The installation of rain drainage was also important in reducing rain penetration. The experimental results suggest that, with proper configurations of its components, a gravity ventilator can be used for natural ventilation without significant rain penetration problems.

  12. Analysis of trials comparing High Frequency Ventilation with Conventional Mechanical Ventilation : Clinical Epidemiology in Intensive Care

    NARCIS (Netherlands)

    Bollen, C.W.

    2006-01-01

    An abundance of experimental and clinical evidence indicates that mechanical ventilation can cause ventilator induced lung damage (VILI). Primary mechanisms leading to VILI are volutrauma, i.e. use of large tidal volumes resulting in over-distension, and atelectotrauma, i.e. repetitive closing and

  13. Changes in lung volume and ventilation during surfactant treatment in ventilated preterm infants

    NARCIS (Netherlands)

    Miedema, Martijn; de Jongh, Frans H.; Frerichs, Inez; van Veenendaal, Mariëtte B.; van Kaam, Anton H.

    2011-01-01

    The immediate and regional effects of exogenous surfactant in open lung high-frequency oscillatory ventilated (HFOV) preterm infants are unknown. To assess regional changes in lung volume, mechanics, and ventilation during and after surfactant administration in HFOV preterm infants with respiratory

  14. The hemodynamic and respiratory effects of cuirass ventilation in healthy volunteers: Part 1.

    Science.gov (United States)

    McBride, William T; Ranaldi, Giulia; Dougherty, Mark J; Siciliano, Tommaso; Trethowan, Brian; Elliott, Peter; Rice, Claire; Scolletta, Sabino; Giomarelli, Pierpaolo; Romano, Salvatore Mario; Linton, David M

    2012-10-01

    Negative-pressure ventilation (NPV) by external cuirass (RTX; Deminax Medical Instruments Limited, London, UK) in intubated patients after cardiac surgery improves hemodynamics measured by pulmonary artery catheter (PAC)-based methods, with an increased cardiac output (CO) and stroke volume (SV), without changing the heart rate (HR). The less-invasive pressure recording analytical method (PRAM) (Mostcare; Vytech Health srl, Padova, Italy) allows radial artery-based monitoring of the CO, SV, SV variation, and cardiac cycle efficiency (CCE). The authors investigated the hypothesis that NPV improves PRAM-based hemodynamics and arterial blood gas analysis in spontaneously breathing subjects. A clinical investigation. A teaching hospital. Ten healthy volunteers. Subjects underwent 5 consecutive experimental ventilation modalities lasting 5 minutes: (1) baseline (no cuirass ventilation), (2) mode 1: cuirass ventilation with a continuous negative pressure of -20 cmH(2)O, (3) first rest period (no cuirass ventilation), (4) mode 2: cuirass ventilation in control mode of 12 breaths/min at -20 cmH(2)O, and (5) second rest period. PRAM parameters were analyzed throughout the final minute of each experimental modality, which concluded with arterial blood gas sampling. Both NPV modes significantly reduced HR without changing CO or systemic vascular resistance. Mode 1 significantly increased CCE and decreased SVV. PO(2) decreased in both rest modes compared with baseline. This was prevented by NPV. In 5 smokers, PO(2) significantly increased in the control mode compared with first rest period. The control mode NPV improved oxygenation with a reduced PCO(2) and reciprocally increased pH. Five minutes of NPV improves hemodynamics and oxygenation in healthy subjects. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Ventilation practices in subarachnoid hemorrhage: a cohort study exploring the use of lung protective ventilation.

    Science.gov (United States)

    Marhong, Jonathan D; Ferguson, Niall D; Singh, Jeffrey M

    2014-10-01

    Acute respiratory distress syndrome (ARDS) is common following aneurysmal subarachnoid hemorrhage (SAH), but the influence of mechanical ventilator settings on its development is unclear. We sought to determine adherence to lung protective thresholds in ventilated patients with SAH and describe the association between ventilator settings and subsequent development of ARDS. We conducted a retrospective cohort study of consecutive patients receiving mechanical ventilation within 72 h of SAH at a single academic center. Ventilator settings and blood gas data were collected twice daily for the first 7 days of ventilation along with ICU and hospital outcomes. Lung protective ventilation was defined as follows: tidal volume ≤8 mL/kg of predicted body weight, positive end-expiratory pressure (PEEP) ≥5 cm H(2)O, and peak or plateau pressure ≤30 cm H(2)O. The development of ARDS was ascertained retrospectively by PaO(2)/FiO(2) ≤300 with new bilateral lung opacities on chest X-ray within one day of hypoxemia. We identified 62 patients who underwent early mechanical ventilation following SAH. PS and Continuous Positive Airway Pressure were common ventilator modes with a median tidal volume of 7.8 mL/kg [interquartile range 6.8-8.8], median peak pressure of 14 cm H(2)O [IQR 12-17], and median PEEP of 5 cm H(2)O [IQR 5-6]. Adherence to tidal volumes ≤8 mL/kg was seen in 64 % of all observations and peak pressures lung protective criteria were seen in 58 % of all observations. Thirty-one patients (50 %) were determined to have ARDS. ARDS patients were more frequently ventilated with a peak pressure >30 cm H(2)O (11.3 % of ARDS ventilation days vs. 0 % of non-ARDS ventilation days; p ventilation frequently breathe spontaneously, generating tidal volumes above usual protective thresholds regardless of meeting ARDS criteria. In patients with SAH, the presence of an additional ARDS risk factor should prompt close screening for the development of ARDS and consideration of

  16. Ventilator versus manual hyperinflation in clearing sputum in ventilated intensive care unit patients.

    Science.gov (United States)

    Dennis, Diane; Jacob, Wendy; Budgeon, Charley

    2012-01-01

    The aim of hyperinflation in the ventilated intensive care unit patient is to increase oxygenation, reverse lung collapse and clear sputum. The efficacy and consistency of manual hyperventilation is well supported in the literature, but there is limited published evidence supporting hyperventilation utilising a ventilator. Despite this, a recent survey established that almost 40% of Australian tertiary intensive care units utilise ventilator hyperinflation. The aim of this non-inferiority cross-over study was to determine whether ventilator hyperinflation was as effective as manual hyperinflation in clearing sputum from patients receiving mechanical ventilation using a prescriptive ventilator hyperinflation protocol. Forty-six patients received two randomly ordered physiotherapy treatments on the same day by the same physiotherapist. The efficacy of the hyperinflation modes was measured by sputum wet weight. Secondary measures included compliance, tidal volume, airway pressure and PaO2/FiO2 ratio. There was no difference in wet weight of sputum cleared using ventilator hyperinflation or manual hyperinflation (mean 3.2 g, P=0.989). Further, no difference in compliance (P=0.823), tidal volume (P=0.219), heart rate (P=0.579), respiratory rate (P=0.929) or mean arterial pressure (P=0.593) was detected. A statistically significant difference was seen in mean airway pressure (P=0.002) between techniques. The effect of techniques on the PaO2/FiO2 response ratio was dependent on time (interaction P=0.024). Physiotherapy using ventilator hyperinflation cleared a comparable amount of sputum and was as safe as manual hyperinflation. This research describes a ventilator hyperinflation protocol that will serve as a platform for continued discussion, research and development of its application in ventilated patients.

  17. The Impact of Ventilator-Associated Events in Critically Ill Subjects With Prolonged Mechanical Ventilation.

    Science.gov (United States)

    Kobayashi, Hidetsugu; Uchino, Shigehiko; Takinami, Masanori; Uezono, Shoichi

    2017-11-01

    The Centers for Disease Control and Prevention recently released a surveillance definition for respiratory complications in ventilated patients, ventilator-associated events (VAEs), to replace ventilator-associated pneumonia (VAP). VAEs consist of ventilator-associated conditions (VAC), infection-related ventilator-associated complications (IVAC), and possible VAP. A duration of mechanical ventilation of at least 4 d is required to diagnose VAE. However, the observed duration of mechanical ventilation was mechanical ventilation for ≥ 4 d. This single-center retrospective cohort study was conducted in the general ICU of an academic hospital. We included 407 adult subjects who were admitted to the ICU and required mechanical ventilation for at least 4 d. VAC and IVAC were identified from the electronic medical records. VAP was defined according to the Centers for Disease Control and Prevention 2008 criteria and was identified from the surveillance data of the infection control team of our hospital. Clinical outcomes were studied in the VAC, IVAC, and VAP groups. Possible VAP was not investigated. Higher mortality was seen in VAC and IVAC subjects, but not in VAP subjects, compared with those without VAEs and VAP. By multivariable hazard analysis for hospital mortality, IVAC was independently associated with hospital mortality (hazard ratio 2.42, 95% CI 1.39-4.20, P = .002). VAC also tended to show a similar association with hospital mortality (hazard ratio 1.45, 95% CI 0.97-2.18, P = .07). On the other hand, VAP did not increase a hazard of hospital death (hazard ratio 1.08, 95% CI 0.44-2.66, P = .87). We found that a VAE was related to hospital mortality in critically ill subjects with prolonged mechanical ventilation, and that VAP was not. Copyright © 2017 by Daedalus Enterprises.

  18. Image-based monitoring of one-lung ventilation.

    Science.gov (United States)

    Jean, S; Cinel, I; Gratz, I; Tay, C; Lotano, V; Deal, E; Parrillo, J E; Dellinger, R P

    2008-12-01

    With the increasing demand for one-lung ventilation in both thoracic surgery and other procedures, identifying the correct placement becomes increasingly important. Currently, endobronchial intubation is suspected based on a combination of auscultation and physiological findings. We investigated the ability of the visual display of airflow-induced vibrations to detect single-lung ventilation with a double-lumen endotracheal tube. Double-lumen tubes were placed prior to surgery. Tracheal and endobronchial lumens were alternately clamped to produce unilateral lung ventilation of right and left lung. Vibration response imaging, which detects vibrations transmitted to the surface of the thorax, was performed during both right- and left-lung ventilation. Geographical area of vibration response image as well as amount and distribution of lung sounds were assessed. During single-lung ventilation, the image and video obtained from the vibration response imaging identifies the ventilated lung with a larger and darker image on the ventilated side. During single-lung ventilation, 87.2 +/- 5.7% of the measured vibrations was detected over the ventilated lung and 12.8 +/- 5.7% over the non-ventilated lung (P single-lung ventilation, the vibration distribution in the non-ventilated lung had a majority of vibration detected by the medial sensors closest to the midline (P lung is ventilated. During single-lung ventilation, vibration response imaging clearly showed increased vibration in the lung that is being ventilated. Distribution of residual vibration differed in the non-ventilated lung in a manner that suggests transmission of vibrations across the mediastinum from the ventilated lung. The lung image and video obtained from vibration response imaging may provide useful and immediate information to help one-lung ventilation assessment.

  19. Low resource ventilation unit; Ressourcebesparende ventilationsenhed

    Energy Technology Data Exchange (ETDEWEB)

    Drivsholm, C.

    2012-03-15

    In the project a resource-saving ventilation device was developed which is based on the use of a regenerator and a reversible air flow. The regenerator is placed in the building envelope, and the concept works in the way that the heat in the air during ventilation is stored in the regenerator and brought back into the building by a reversible air change. The heated air is blown from inside the building out through the regenerator. In this way the regenerator accumulates the heat in the air. Over a period of 30-120 seconds, the regenerator capacity is utilized. When the regenerator cannot be further heated, the air flow is reversed and there is now blown cold air through the regenerator. Thereby the heat from the regenerator is released to the cold fresh air. Thus, the fresh air brings heat back into the building, whereby the air is replaced with a limited heat loss. Ventilation with a regenerator is described as micro-ventilation. The developed micro-ventilation unit was tested by the Danish Technological Institute. The test results shows that the unit performs according to expectations: 1) The heat recovery is 85%; 2) The flow through the unit is 80m3 per hour in a 5 section unit; 3) The noise level is 30 db(A) in a representative room; 4) The energy consumption is <300 J/m3. The unit is introduced into the market, and the first plants have been sold. (LN)

  20. Intelligent decision support systems for mechanical ventilation.

    Science.gov (United States)

    Tehrani, Fleur T; Roum, James H

    2008-11-01

    An overview of different methodologies used in various intelligent decision support systems (IDSSs) for mechanical ventilation is provided. The applications of the techniques are compared in view of today's intensive care unit (ICU) requirements. Information available in the literature is utilized to provide a methodological review of different systems. Comparisons are made of different systems developed for specific ventilation modes as well as those intended for use in wider applications. The inputs and the optimized parameters of different systems are discussed and rule-based systems are compared to model-based techniques. The knowledge-based systems used for closed-loop control of weaning from mechanical ventilation are also described. Finally, in view of increasing trend towards automation of mechanical ventilation, the potential utility of intelligent advisory systems for this purpose is discussed. IDSSs for mechanical ventilation can be quite helpful to clinicians in today's ICU settings. To be useful, such systems should be designed to be effective, safe, and easy to use at patient's bedside. In particular, these systems must be capable of noise removal, artifact detection and effective validation of data. Systems that can also be adapted for closed-loop control/weaning of patients at the discretion of the clinician, may have a higher potential for use in the future.

  1. Improving comfort and health with personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor

    2004-01-01

    The thermal environment and air quality in buildings affects occupants¿ health, comfort and performance. The heating, ventilating and air-conditioning (HVAC) of buildings today is designed to provide a uniform room environment. However, large individual differences exist between occupants in regard...... microenvironment. Furthermore, HVAC systems should be designed to protect occupants from airborne transmission of infectious agents that may be present in exhaled air. Personalized ventilation is a new development in the field of HVAC and has the potential to fulfil the above requirements. This paper reviews...... existing knowledge on performance of personalized ventilation (PV) and on human response to it. The airflow interaction in the vicinity of the human body is analysed and its impact on thermal comfort and inhaled air quality is discussed together with control strategies and the application of PV in practice...

  2. Personal Exposure in Displacement Ventilated Rooms

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter Vilhelm

    1996-01-01

    in the lower part of the room close to the occupant. A personal exposure model for displacement ventilated rooms is proposed. The model takes the influence of gradients and the human thermal boundary layer into account. Two new quantities describing the interaction between a person and the ventilation......Personal exposure in a displacement ventilated room is examined. The stratified flow and the considerable concentration gradients necessitate an improvement of the widely used fully mixing compartmental approach. The exposure of a seated and a standing person in proportion to the stratification...... height is examined by means of full-scale measurements. A breathing thermal manikin is used to simulate a person. It is found that the flow in the boundary layer around a person is able to a great extent to entrain and transport air from below the breathing zone. In the case of non-passive, heated...

  3. Home Mechanical Ventilation in South Korea

    Science.gov (United States)

    Kim, Dong Hyun; Choi, Won Ah

    2014-01-01

    Purpose To survey the use of invasive and noninvasive home mechanical ventilation (HMV) methods in South Korea from the perspective of physical medicine and rehabilitation (PM&R). Materials and Methods For 413 users of HMV, retrospective reviews of PM&R interventions and survey of HMV methods employed from Mar 2000 to Dec 2009. Results Of the 413 users, the majority of whom with progressive neuromuscular disorders (NMDs) (n=358), 284 patients initially used noninvasive mechanical ventilation (NIV), while 63 others who were using tracheostomy mechanical ventilation switched to NIV as part of their rehabilitation. The NMD patients began HMV at an earlier age (34.9±20.3 yrs), and used for longer (14.7±7.5) hours than patients with non-neuromuscular causes of respiratory impairment. Conclusion Noninvasive management was preferred over invasive ones, and transition to the former was a result of PM&R interventions. PMID:25323913

  4. Energy Analysis of the Ductless Personalized Ventilation

    DEFF Research Database (Denmark)

    Lelong, Cyril; Dalewski, Mariusz; Melikov, Arsen Krikor

    2013-01-01

    This study explores the impact of different occupancy profiles on the potential energy savings due to using ductless personalized ventilation (DPV) combined with displacement ventilation. Energy simulations were performed with the dynamic simulation software IDA-ICE in order to investigate optimal...... energy efficient strategies for implantation of DPV in practice. The impact of using DPV on annual energy use has been studied for different occupancy profiles in cold climates. The results suggest that using DPV combined with displacement ventilation may significantly reduce building energy use while...... providing good air quality and thermal comfort for the occupants. Matching DPV use with occupants’ presence at their workplaces may allow reducing the energy use of DPV significantly....

  5. Phrenic pacing compared with mechanical ventilation

    DEFF Research Database (Denmark)

    Andersen, Morten Packert; Laub, Michael; Biering-Sørensen, Fin

    2017-01-01

    mechanical ventilator dependent tetraplegics met the inclusion criteria. Data were retrieved from medical records and a structured follow-up interview with seven individuals from each group. RESULTS: No significant differences were found when comparing age at injury, time since injury, length...... of hospitalization, incidence of pneumonia, number of pneumonia hospitalizations, number of tracheal suctions, speech quality and activities of daily living or quality of life. On the Short Form Health Survey (SF36) mental health summary the median for both users of phrenic nerve pacing and users of mechanical...... ventilation was one s.d. above the mean of a standard population. CONCLUSIONS: Nine people have had a phrenic nerve pacer implanted. They do not significantly differ from a group of home mechanical ventilator dependent tetraplegics on a number of performance measures, but both groups seem to have better...

  6. Performance of displacement ventilation in practice

    DEFF Research Database (Denmark)

    Naidenov, K.; Pitchurov, G.; Langkilde, Gunnar

    2002-01-01

    This paper presents results of a field study in offices with displacement ventilation. It comprises detailed physical measurements of the thermal environment and collection of occupants´ response at 227 workplaces. The results, both physical measurements and human response, identified draught...... as the major local discomfort in the rooms with displacement ventilation. Twenty-three percent of the occupants were daily bothered by draught. In some buildings the maintenance personnel tried to improve occupants´ thermal comfort by raising the supply air temperature or office workers themselves blocked...... the diffusers by rearranging the furniture. Half of the surveyed occupants were not satisfied with the indoor air quality. The main conclusion is that displacement ventilation needs careful design and room furnishing in order to ensure a comfortable environment. Occupants must understand the underlying...

  7. Multiple factors influencing OR ventilation system effectiveness

    Directory of Open Access Journals (Sweden)

    Buhl Sebastian

    2016-09-01

    Full Text Available The issue of surgical site infections has become more critical during the last years. The number of airborne microbes depends on the number released by the staff in the room or supplied from neighbouring rooms. In order to minimize the risk of nosocomial infections during surgical procedures technical developments like ventilation systems were introduced in the operating room (OR. In this study several factors like clothing and types of ventilation systems have been investigated and their impact on the effectiveness for reducing microbial burden in the OR has been assessed. In case of OR-gowns we found a benefit for a disposable Swedish clothing concept regarding microbiological contamination in comparison with the German standard multiuse clothing. Moreover our study shows that there is comparable effectiveness of a fairly novel temperature controlled airflow ventilation system (TAF compared to standard low turbulent uni-directional airflow (TAV.

  8. Core body temperature control by total liquid ventilation using a virtual lung temperature sensor.

    Science.gov (United States)

    Nadeau, Mathieu; Micheau, Philippe; Robert, Raymond; Avoine, Olivier; Tissier, Renaud; Germim, Pamela Samanta; Vandamme, Jonathan; Praud, Jean-Paul; Walti, Herve

    2014-12-01

    In total liquid ventilation (TLV), the lungs are filled with a breathable liquid perfluorocarbon (PFC) while a liquid ventilator ensures proper gas exchange by renewal of a tidal volume of oxygenated and temperature-controlled PFC. Given the rapid changes in core body temperature generated by TLV using the lung has a heat exchanger, it is crucial to have accurate and reliable core body temperature monitoring and control. This study presents the design of a virtual lung temperature sensor to control core temperature. In the first step, the virtual sensor, using expired PFC to estimate lung temperature noninvasively, was validated both in vitro and in vivo. The virtual lung temperature was then used to rapidly and automatically control core temperature. Experimentations were performed using the Inolivent-5.0 liquid ventilator with a feedback controller to modulate inspired PFC temperature thereby controlling lung temperature. The in vivo experimental protocol was conducted on seven newborn lambs instrumented with temperature sensors at the femoral artery, pulmonary artery, oesophagus, right ear drum, and rectum. After stabilization in conventional mechanical ventilation, TLV was initiated with fast hypothermia induction, followed by slow posthypothermic rewarming for 1 h, then by fast rewarming to normothermia and finally a second fast hypothermia induction phase. Results showed that the virtual lung temperature was able to provide an accurate estimation of systemic arterial temperature. Results also demonstrate that TLV can precisely control core body temperature and can be favorably compared to extracorporeal circulation in terms of speed.

  9. SUPRAGLOTTIC JET VENTILATION VERSUS CONVENTIONAL ENDOTRACHEAL VENTILATION IN MINOR LARYNGEAL SURGERIES

    Directory of Open Access Journals (Sweden)

    Illendual Upendranath

    2016-08-01

    Full Text Available Any attempt at intubation will cause many cardiovascular responses and the major concern during this time is to attenuate the same. Similar response is seen during procedures on Larynx in microlaryngeal surgery which produces an intense cardiovascular stimulation during suspension laryngoscopy and intubation. AIM OF STUDY Supraglottic jet ventilation versus conventional endotracheal ventilation in minor laryngeal surgeries. To evaluate the haemodynamic response in supraglottic jet ventilation and conventional intubation in minor laryngeal surgeries. METHODS Patients were randomised to 2 Groups: 30 patients in each group; Group A - in whom supraglottic jet ventilation was planned and Group B - in whom endotracheal intubation was planned. RESULT The haemodynamic response in terms of increase in MAP and HR is significantly more with endotracheal intubation than with supraglottic jet ventilation. CONCLUSION Our study showed that supraglottic jet ventilation showed a better haemodynamic stability when compared to conventional endotracheal intubation in patients undergoing minor laryngeal surgeries. Statistical scores were also in favour of the patients treated with supraglottic jet ventilation based on the p values.

  10. Demand-controlled mechanical ventilation. Behovsstyret mekanisk ventilation; Fugt som reguleringsparameter - et pilotprojekt

    Energy Technology Data Exchange (ETDEWEB)

    1992-06-01

    This report presents the results from the registration throughout a month of relative humidity, temperature and outdoor air exchanger as well as the concentration of carbon dioxide in each room of an inhabited single family house, in which all rooms are ventilated by a mechanical balanced ventilation system with variable air volume. The ventilation outdoor air rate is controlled by the relative humidity, which is kept on a value adequate to reduce the living conditions for house dust mites and prevent condensation on the indoor surfaces of the building. Due to the demand control ventilation of each individual room a higher efficiency for reducing water vapors in the dwelling as a whole is likely to be achieved. The results show that it is possible with this kind of ventilation system and in the context of Danish outdoor climate to maintain humidity conditions that is anticipated to reduce the number of house dust mites in all rooms of a dwelling during more than five months of the year. In all the months the mean daily mechanical ventilation rate is estimated to be 39% below the level recommended in the Danish Building Code. At the same time indoor condensation was avoided on poorly insulated surfaces of the building. The concentration of carbon dioxide was below the level recommended in international ventilation standards. (au) (13 refs.)

  11. Ventilator gas flow rates affect inspiratory time and ventilator efficiency index in term lambs.

    Science.gov (United States)

    Bach, Katinka P; Kuschel, Carl A; Oliver, Mark H; Bloomfield, Frank H

    2009-01-01

    Despite increasing survival in the smallest preterm infants, the incidence of chronic lung disease has not decreased. Research into ventilatory strategies has concentrated on minimising barotrauma, volutrauma and atelectotrauma, but little attention has been paid to the role of bias gas flow rates and the potential for rheotrauma or shear stress injury. Ventilated preterm infants frequently receive relatively high gas flow rates. We hypothesised that altering bias gas flow rates would change the efficiency of ventilation and thereby affect ventilatory parameters. We tested this hypothesis using an artificial lung followed by ventilation of 8 term lambs. Between flows of 2 and 15 l/min, inflation time (Ti) in the artificial lung was inversely related to the bias gas flow rate. In the ventilated lambs, Ti was inversely related to flow rates up to 10 l/min, with no statistically significant effect at flow rates >10 l/min. There were no adverse effects on gas exchange or cardiovascular parameters until a flow rate of 3 l/min was used, when inadequate gas exchange occurred. Ti is inversely associated with the bias gas flow rate. Flow rates much lower than those used in many neonatal units seem to provide adequate ventilation. We suggest that the role of ventilator gas flow rates, which may potentially influence shear stress in ventilator-induced lung injury, merits further investigation. Copyright 2009 S. Karger AG, Basel.

  12. Trends in mechanical ventilation: are we ventilating our patients in the best possible way?

    Science.gov (United States)

    Veneroni, Chiara; Farre’, Ramon

    2017-01-01

    This review addresses how the combination of physiology, medicine and engineering principles contributed to the development and advancement of mechanical ventilation, emphasising the most urgent needs for improvement and the most promising directions of future development. Several aspects of mechanical ventilation are introduced, highlighting on one side the importance of interdisciplinary research for further development and, on the other, the importance of training physicians sufficiently on the technological aspects of modern devices to exploit properly the great complexity and potentials of this treatment. Educational aims To learn how mechanical ventilation developed in recent decades and to provide a better understanding of the actual technology and practice. To learn how and why interdisciplinary research and competences are necessary for providing the best ventilation treatment to patients. To understand which are the most relevant technical limitations in modern mechanical ventilators that can affect their performance in delivery of the treatment. To better understand and classify ventilation modes. To learn the classification, benefits, drawbacks and future perspectives of automatic ventilation tailoring algorithms. PMID:28620428

  13. Thermoregulation and ventilation of termite mounds

    Science.gov (United States)

    Korb, Judith

    2003-05-01

    Some of the most sophisticated of all animal-built structures are the mounds of African termites of the subfamily Macrotermitinae, the fungus-growing termites. They have long been studied as fascinating textbook examples of thermoregulation or ventilation of animal buildings. However, little research has been designed to provide critical tests of these paradigms, derived from a very small number of original papers. Here I review results from recent studies on Macrotermes bellicosus that considered the interdependence of ambient temperature, thermoregulation, ventilation and mound architecture, and that question some of the fundamental paradigms of termite mounds. M. bellicosus achieves thermal homeostasis within the mound, but ambient temperature has an influence too. In colonies in comparably cool habitats, mound architecture is adapted to reduce the loss of metabolically produced heat to the environment. While this has no negative consequences in small colonies, it produces a trade-off with gas exchange in large colonies, resulting in suboptimally low nest temperatures and increased CO2 concentrations. Along with the alteration in mound architecture, the gas exchange/ventilation mechanism also changes. While mounds in the thermally appropriate savannah have a very efficient circular ventilation during the day, the ventilation in the cooler forest is a less efficient upward movement of air, with gas exchange restricted by reduced surface exchange area. These results, together with other recent findings, question entrenched ideas such as the thermosiphon-ventilation mechanism or the assumption that mounds function to dissipate internally produced heat. Models trying to explain the proximate mechanisms of mound building, or building elements, are discussed.

  14. Advanced design of local ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Kulmala, I. [VTT Manufacturing Technology, Espoo (Finland). Safety Technology

    1997-12-31

    Local ventilation is widely used in industry for controlling airborne contaminants. However, the present design practices of local ventilation systems are mainly based on empirical equations and do not take quantitatively into account the various factors affecting the performance of these systems. The aim of this study was to determine the applicability and limitations of more advanced fluid mechanical methods to the design and development of local ventilation systems. The most important factors affecting the performance of local ventilation systems were determined and their effect was studied in a systematic manner. The numerical calculations were made with the FLUENT computer code and they were verified by laboratory experiments, previous measurements or analytical solutions. The results proved that the numerical calculations can provide a realistic simulation of exhaust openings, effects of ambient air flows and wake regions. The experiences with the low-velocity local supply air showed that these systems can also be modelled fairly well. The results were used to improve the efficiency and thermal comfort of a local ventilation unit and to increase the effective control range of exhaust hoods. In the simulation of the interaction of a hot buoyant source and local exhaust, the predicted capture efficiencies were clearly higher than those observed experimentally. The deviations between measurements and non-isothermal flow calculations may have partly been caused by the inability to achieve grid independent solutions. CFD simulations is an advanced and flexible tool for designing and developing local ventilation. The simulations can provide insight into the time-averaged flow field which may assist us in understanding the observed phenomena and to explain experimental results. However, for successful calculations the applicability and limitations of the models must be known. (orig.) 78 refs.

  15. Diffusion tensor imaging detects ventilation-induced brain injury in preterm lambs.

    Directory of Open Access Journals (Sweden)

    Dhafer M Alahmari

    Full Text Available Injurious mechanical ventilation causes white matter (WM injury in preterm infants through inflammatory and haemodynamic pathways. The relative contribution of each of these pathways is not known. We hypothesised that in vivo magnetic resonance imaging (MRI can detect WM brain injury resulting from mechanical ventilation 24 h after preterm delivery. Further we hypothesised that the combination of inflammatory and haemodynamic pathways, induced by umbilical cord occlusion (UCO increases brain injury at 24 h.Fetuses at 124±2 days gestation were exposed, instrumented and either ventilated for 15 min using a high tidal-volume (VT injurious strategy with the umbilical cord intact (INJ; inflammatory pathway only, or occluded (INJ+UCO; inflammatory and haemodynamic pathway. The ventilation groups were compared to lambs that underwent surgery but were not ventilated (Sham, and lambs that did not undergo surgery (unoperated control; Cont. Fetuses were placed back in utero after the 15 min intervention and ewes recovered. Twenty-four hours later, lambs were delivered, placed on a protective ventilation strategy, and underwent MRI of the brain using structural, diffusion tensor imaging (DTI and magnetic resonance spectroscopy (MRS techniques.Absolute MRS concentrations of creatine and choline were significantly decreased in INJ+UCO compared to Cont lambs (P = 0.03, P = 0.009, respectively; no significant differences were detected between the INJ or Sham groups and the Cont group. Axial diffusivities in the internal capsule and frontal WM were lower in INJ and INJ+UCO compared to Cont lambs (P = 0.05, P = 0.04, respectively. Lambs in the INJ and INJ+UCO groups had lower mean diffusivities in the frontal WM compared to Cont group (P = 0.04. DTI colour mapping revealed lower diffusivity in specific WM regions in the Sham, INJ, and INJ+UCO groups compared to the Cont group, but the differences did not reach significance. INJ+UCO lambs more likely to exhibit

  16. Determinants of Receiving Palliative Care and Ventilator Withdrawal Among Patients With Prolonged Mechanical Ventilation.

    Science.gov (United States)

    Chen, Yang-Ching; Fan, Hsien-Yu; Curtis, J Randall; Lee, Oscar Kuang-Sheng; Liu, Chih-Kuang; Huang, Sheng-Jean

    2017-10-01

    Increasing numbers of patients with prolonged mechanical ventilation generates a tremendous strain on healthcare systems. Patients with prolonged mechanical ventilation suffer from long-term poor quality of life. However, no study has ever explored the willingness to receive palliative care or terminal withdrawal and the factors influencing willingness. Cross-sectional study. Five different hospitals of Taipei City Hospital system. Adult patients with ventilatory support for more than 60 days. None. We identified the family members of 145 consecutive patients with prolonged mechanical ventilation in five hospitals of Taipei City Hospital system and enrolled family members for 106 patients (73.1%). We collected information from patient families' regarding concepts (knowledge, attitude, and experiences) of palliative care, caregiver burden, family function, patient quality of life, and physician-family communications. From the medical record, we obtained duration of hospitalization, consciousness level, disease severity, medical cost, and the presence of do-not-resuscitate orders. The vast majority of family members agreed with the concept of palliative care (90.4%) with 17.3% of the family members agreeing to ventilator withdrawal currently and 67.5% terminally in anticipation of death. Approximately half of the family members regretted having chosen prolonged mechanical ventilation (56.7%). Reduced patient quality of life and increased family understanding of palliative care significantly associated with increased caregiver willingness to endorse palliative care and withdraw life-sustaining agents in anticipation of death. Longer duration of ventilator usage and hospitalization was associated with increased feelings of regret about choosing prolonged mechanical ventilation. During prolonged mechanical ventilation, physicians should thoroughly discuss its benefits and burdens. Families should be given the opportunity to discuss the circumstances under which they

  17. IOT Overview: IR Instruments

    Science.gov (United States)

    Mason, E.

    In this instrument review chapter the calibration plans of ESO IR instruments are presented and briefly reviewed focusing, in particular, on the case of ISAAC, which has been the first IR instrument at VLT and whose calibration plan served as prototype for the coming instruments.

  18. Preoperational test report, recirculation ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  19. Design of Energy Efficient Hybrid Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The focus in the development has for both systems been to minimise energy consumption while maintaining a comfortable and healthy indoor environment. The natural next step in this development is to develop ventilation concepts that utilises and combines the best features from each system[Mechanic......The focus in the development has for both systems been to minimise energy consumption while maintaining a comfortable and healthy indoor environment. The natural next step in this development is to develop ventilation concepts that utilises and combines the best features from each system...

  20. Ductless personalized ventilation with local air cleaning

    OpenAIRE

    Dalewski, Mariusz; Vesely, Michal; Melikov, Arsen Krikor

    2012-01-01

    An experiment with 28 human subjects was performed to examine effects of using a local air cleaning device combined with ductless personalized ventilation (DPV) on perceived air quality. Experiments were performed in a test room with displacement ventilation. The DPV at one of two desks was equipped with an activated carbon filter installed at the air intake, while the DPV at the second desk was without such a filter. The air temperature in the occupied zone (1.1 m above the floor) was 29 °C....

  1. No-sedation during mechanical ventilation

    DEFF Research Database (Denmark)

    Laerkner, Eva; Stroem, Thomas; Toft, Palle

    2016-01-01

    BACKGROUND: Evidence is growing that less or no-sedation is possible and beneficial for patients during mechanical ventilation. AIM: To investigate if there was a difference in patient consciousness and nursing workload comparing a group of patients receiving no-sedation with a group of sedated...... patients with daily wake up, and also to estimate economic consequences of a no-sedation strategy. DESIGN AND METHODS: Data were collected during a prospective trial of 140 mechanically ventilated patients randomized to either no-sedation or to sedation with daily wake up. From day 1 to 7 in the intensive...

  2. Achieving Natural and Hybrid Ventilation in Practice

    DEFF Research Database (Denmark)

    Liddament, Martin; Axley, James; Heiselberg, Per

    2006-01-01

    Case studies provide essential evidence about the performance of buildings. They also illustrate the methods by which a technology can be implemented as well as highlighting problems. Various case study buildings (both new and retrofit) that incorporate mixed mode, natural ventilation and low...... energy cooling are reviewed in this paper. An outline of the tasks that ventilation is required to perform is also presented. The results show that many buildings perform well and can provide good thermal comfort and air quality for much of the occupied period. Various solutions have been introduced...

  3. Sedation and analgesia to facilitate mechanical ventilation.

    Science.gov (United States)

    Nemergut, Michael E; Yaster, Myron; Colby, Christopher E

    2013-09-01

    Regardless of age, health care professionals have a professional and ethical obligation to provide safe and effective analgesia to patients undergoing painful procedures. Historically, newborns, particularly premature and sick infants, have been undertreated for pain. Intubation of the trachea and mechanical ventilation are ubiquitous painful procedures in the neonatal intensive care unit that are poorly assessed and treated. The authors review the use of sedation and analgesia to facilitate endotracheal tube placement and mechanical ventilation. Controversies regarding possible adverse neurodevelopmental outcomes after sedative and anesthetic exposure and in the failure to treat pain is also discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Astronomical Instruments in India

    Science.gov (United States)

    Sarma, Sreeramula Rajeswara

    The earliest astronomical instruments used in India were the gnomon and the water clock. In the early seventh century, Brahmagupta described ten types of instruments, which were adopted by all subsequent writers with minor modifications. Contact with Islamic astronomy in the second millennium AD led to a radical change. Sanskrit texts began to lay emphasis on the importance of observational instruments. Exclusive texts on instruments were composed. Islamic instruments like the astrolabe were adopted and some new types of instruments were developed. Production and use of these traditional instruments continued, along with the cultivation of traditional astronomy, up to the end of the nineteenth century.

  5. Health physics instrument manual

    Energy Technology Data Exchange (ETDEWEB)

    Gupton, E.D.

    1978-08-01

    The purpose of this manual is to provide apprentice health physics surveyors and other operating groups not directly concerned with radiation detection instruments a working knowledge of the radiation detection and measuring instruments in use at the Laboratory. The characteristics and applications of the instruments are given. Portable instruments, stationary instruments, personnel monitoring instruments, sample counters, and miscellaneous instruments are described. Also, information sheets on calibration sources, procedures, and devices are included. Gamma sources, beta sources, alpha sources, neutron sources, special sources, a gamma calibration device for badge dosimeters, and a calibration device for ionization chambers are described. (WHK)

  6. Weaning Automation with Adaptive Support Ventilation: A Randomized Controlled Trial in Cardiothoracic Surgery Patients

    NARCIS (Netherlands)

    Dongelmans, Dave A.; Veelo, Denise P.; Paulus, Frederique; de Mol, Bas A. J. M.; Korevaar, Johanna C.; Kudoga, Anna; Middelhoek, Pauline; Binnekade, Jan M.; Schultz, Marcus J.

    2009-01-01

    Background: Adaptive support ventilation (ASV) is a microprocessor-controlled mode of mechanical ventilation that switches automatically from controlled ventilation to assisted ventilation and selects ventilatory settings according to measured lung mechanics. Methods: In a randomized controlled

  7. Thermal comfort and ventilation effectiveness in an office room with radiant floor cooling and displacement ventilation

    DEFF Research Database (Denmark)

    Krajcik, Michal; Tomasi, Roberta; Simone, Angela

    2016-01-01

    retain the favorable air and temperature distribution patterns and high ventilation effectiveness that are typically attained by displacement ventilation, while exploiting the energy conservation advantages of a high temperature cooling system. The tests were performed under a range of boundary......The influence of displacement ventilation and a cooled floor on indoor climate in the cooling season were experimentally studied in a room representing an office with a shaded window, occupied by two simulated employees. The aim was to investigate whether the combination of these two systems can...

  8. Efficient ventilation in school buildings. Design guidebook; Ventilation performante dans les ecoles. Guide de conception

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This guidebook aims at giving practical advices for the design of ventilation systems for school buildings in order to maintain air quality levels and energy consumptions conformable with the real needs: 1 - the specific problem of schools (various types of rooms, particular indoor pollutions); 2 - main criteria to consider (air quality and hygiene, hygro-thermal comfort, ventilation efficiency, acoustic comfort, energy mastery); 3 - main existing solutions (simple-flux blow-off or blow-in mechanical ventilation systems, dual-flux systems, air conditioning systems); 4 - choice of an adapted solution (selection criteria, global solution for the school); setting-up and follow-up (rules, training, maintenance). (J.S.)

  9. [Comparative studies of the circulatory system during high frequency inspiratory ventilation and inspiratory positive pressure ventilation].

    Science.gov (United States)

    Nestorowicz, A; Powała-Niedźwiecki, K

    1989-02-06

    The studies were carried out in 14 dogs in which two different ventilation techniques were used under the general anaesthesia: HFIV and IPPV. Functioning of the cardio-vascular system was evaluated, basing on the measurements of pulse rate, pressure in the peripheral vessels, pulmonary artery and central venous pressure and calculation of the stroke volume, cardiac index, and pulmonary vessels resistance index. It was found that both techniques of ventilation did not exert any effect on the functioning of cardio-vascular system. Stroke volume was lower during IPPV than that during HFIV ventilation.

  10. Chest trauma: A case for single lung ventilation

    National Research Council Canada - National Science Library

    Pandharikar, Nagaraj; Sachdev, Anil; Gupta, Neeraj; Gupta, Suresh; Gupta, Dhiren

    2016-01-01

    .... The complexity, magnitude, and type of lung injury make it extremely challenging to provide optimal oxygenation and ventilation while protecting the lung from further injury due to mechanical ventilation...

  11. Elective ventilation for organ donation: law, policy and public ethics.

    Science.gov (United States)

    Coggon, John

    2013-03-01

    This paper examines questions concerning elective ventilation, contextualised within English law and policy. It presents the general debate with reference both to the Exeter Protocol on elective ventilation, and the considerable developments in legal principle since the time that that protocol was declared to be unlawful. I distinguish different aspects of what might be labelled elective ventilation policies under the following four headings: 'basic elective ventilation'; 'epistemically complex elective ventilation'; 'practically complex elective ventilation'; and 'epistemically and practically complex elective ventilation'. I give a legal analysis of each. In concluding remarks on their potential practical viability, I emphasise the importance not just of ascertaining the legal and ethical acceptability of these and other forms of elective ventilation, but also of assessing their professional and political acceptability. This importance relates both to the successful implementation of the individual practices, and to guarding against possible harmful effects in the wider efforts to increase the rates of posthumous organ donation.

  12. Indoor Air Quality: Is Increased Ventilation the Answer?

    Science.gov (United States)

    Hansen, Shirley

    1989-01-01

    Explains how indoor air quality is affected by pollutants in the air and also by temperature, humidity, and ventilation. Increased ventilation alone seldom solves the "sick building syndrome." Lists ways to improve indoor air quality and optimize energy efficiency. (MLF)

  13. 30 CFR 75.330 - Face ventilation control devices.

    Science.gov (United States)

    2010-07-01

    ... control devices. (a) Brattice cloth, ventilation tubing and other face ventilation control devices shall... maintaining concentrations of respirable dust, methane, and other harmful gases, in accordance with the levels...

  14. The lived experience of patients on mechanical ventilation: research ...

    African Journals Online (AJOL)

    1994: 152). An independent coder verified the identified major themes, namely: experiences of patients related to the process of ventilation, as well as their experiences of the environment while connected to the ventilator. A literature control ...

  15. Dimensionless study on dynamics of pressure controlled mechanical ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yan; Niu, Jinglong; Cai, Maolin; Xu, Weiqing [Beihang University, Beijing (Korea, Republic of)

    2015-02-15

    Dynamics of mechanical ventilation system can be referred in pulmonary diagnostics and treatments. In this paper, to conveniently grasp the essential characteristics of mechanical ventilation system, a dimensionless model of mechanical ventilation system is presented. For the validation of the mathematical model, a prototype mechanical ventilation system of a lung simulator is proposed. Through the simulation and experimental studies on the dimensionless dynamics of the mechanical ventilation system, firstly, the mathematical model is proved to be authentic and reliable. Secondly, the dimensionless dynamics of the mechanical ventilation system are obtained. Last, the influences of key parameters on the dimensionless dynamics of the mechanical ventilation system are illustrated. The study provides a novel method to study the dynamic of mechanical ventilation system, which can be referred in the respiratory diagnostics and treatment.

  16. Mechanical ventilation in neurocritical care patients: a systematic literature review

    NARCIS (Netherlands)

    Borsellino, Beatrice; Schultz, Marcus J.; Gama de Abreu, Marcelo; Robba, Chiara; Bilotta, Federico

    2016-01-01

    Neurocritical care (NCC) patients often require prolonged mechanical ventilation, and they are at high risk of respiratory complications. Therefore, the potential benefit role of protective lung ventilation (PLV), which demonstrated to reduce postoperative complications in patients with acute

  17. Hypoxia in a neonate caused by intermittent positive pressure ventilation.

    OpenAIRE

    Beddis, I R; Silverman, M

    1980-01-01

    A newborn baby receiving mechanical ventilation was noted to have an extremely variable degree of hypoxia, despite the administration of 100% oxygen. The hypoxia was relieved rapidly when mechanical ventilation was withdrawn.

  18. Lung Transplantation for Ventilator-Dependent Respiratory Failure

    NARCIS (Netherlands)

    Vermeijden, J. Wytze; Zijlstra, Jan G.; Erasmus, Michiel E.; van der Bij, Wim; Verschuuren, Erik A.

    Introduction: Lung transplantation of patients on mechanical ventilation is controversial, but successful transplantation of these patients has been reported. This report describes our institutional experience with lung transplantation of mechanically Ventilated patients since 2003. Methods: A

  19. Adaptive support ventilation: State of the art review.

    Science.gov (United States)

    Fernández, Jaime; Miguelena, Dayra; Mulett, Hernando; Godoy, Javier; Martinón-Torres, Federico

    2013-01-01

    Mechanical ventilation is one of the most commonly applied interventions in intensive care units. Despite its life-saving role, it can be a risky procedure for the patient if not applied appropriately. To decrease risks, new ventilator modes continue to be developed in an attempt to improve patient outcomes. Advances in ventilator modes include closed-loop systems that facilitate ventilator manipulation of variables based on measured respiratory parameters. Adaptive support ventilation (ASV) is a positive pressure mode of mechanical ventilation that is closed-loop controlled, and automatically adjust based on the patient's requirements. In order to deliver safe and appropriate patient care, clinicians need to achieve a thorough understanding of this mode, including its effects on underlying respiratory mechanics. This article will discuss ASV while emphasizing appropriate ventilator settings, their advantages and disadvantages, their particular effects on oxygenation and ventilation, and the monitoring priorities for clinicians.

  20. The Effects of Ventilation in Homes on Health

    DEFF Research Database (Denmark)

    Wargocki, Pawel

    2013-01-01

    and to reduce emissions. Often, especially in existing buildings, this strategy is difficult to implement, in which case exposures are controlled by providing sufficient, presumably clean, outdoor ventilation air to dilute and remove the contaminants. The present paper attempts to find out how much ventilation...... in existing homes. No data were found indicating that buildings having dedicated natural ventilation systems perform less well than the dwellings in which mechanical ventilation systems are installed. Newly installed mechanical ventilation systems were observed to improve health conditions. In homes...... Guidelines for Indoor Air Quality and improving ventilation measurements). Exposures should also be controlled using different ventilation methods for comparison. Future studies should also advance the understanding of how ventilation systems should be operated to achieve optimal performance. These data...

  1. Evaluating the influence of ventilation and ventilation-compression synchronization on chest compression force and depth during simulated neonatal resuscitation.

    Science.gov (United States)

    Dellimore, K H; Scheffer, C; Smith, J; Van Den Heever, D J; Lloyd, D L

    2017-06-01

    To investigate the influence of ventilation and ventilation-compression synchronization on compression force and sternal displacement during simulated neonatal cardiopulmonary resuscitation (NCPR) on an infant manikin. Five Neonatal Resuscitation Program trained clinicians were recruited to perform simulated NCPR on an infant manikin using two-finger (TF) and two-thumb (TT) compression, with synchronous and asynchronous ventilation, as well as without ventilation. The sternal displacement and force were recorded and analyzed. Synchronous ventilation and compression yielded sternal displacements and forces in the range of 22.8-32.4 mm and 15.0-29.8 N, respectively, while asynchronous ventilation and compression produced depths and forces in the range of 21.2-32.4 mm and 14.0-28.8 N, respectively. Ventilation exerts a significant influence on sternal displacement and force during simulated NCPR, regardless of the compression method used. Ventilation-compression synchronization, however, is only significant during TF compression with lower compression forces measured during synchronous ventilation than in asynchronous ventilation. This occurs for two reasons: (i) the strong influence of ventilation forces on the lower magnitude compression forces produced during TF compression relative to TT compression and (ii) in asynchronous ventilation, compression and ventilation may occur simultaneously, with inflation and deflation providing an opposing force to the applied compression force.

  2. [Controlled mechanical lung ventilation with guaranteed volume in newborns].

    Science.gov (United States)

    Kriakvina, O A; Grebennikov, V A; Tsypin, L E; Volodin, N N

    2011-01-01

    Mechanical ventilation with guaranteed volumes combines advantages of time-cyclic ventilation with limitation of pressure and constant flow, with volume control ventilation. This symbiosis allows to choose the optimal, stable breathing volume of the newborn, while maintaining pressure control. The review presents the principles of work, the main advantages and limitations of ventilation systems with the guaranteed volumes, as well as results and analysis of studies.

  3. Attic Ventilation Guidelines to Minimize Icings at Eaves

    Science.gov (United States)

    1998-01-01

    by sizing natural, and if necessary, mechanical attic ventilation systems to maintain an attictemperature of 30F when the outside temperature is 22F...JAN 1998 2. REPORT TYPE 3. DATES COVERED - 4. TITLE AND SUBTITLE Attic Ventilation Guidelines to Minimize Icings at Eaves 5a. CONTRACT NUMBER...develop on roofs that slope to cold eaves. Ventilating the space below the snow-covered roof with outdoor aur to create a "cold" ventilated roof is

  4. Displacement Ventilation in a Room with Low-Level Diffusers

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Ventilation systems with vertical displacement flow have been used in industrial areas with high thermal loads for many years. Quite resently the vertical displacement flow systems have grown popular as comfort ventilation in rooms with thermal loads e.g. offices.......Ventilation systems with vertical displacement flow have been used in industrial areas with high thermal loads for many years. Quite resently the vertical displacement flow systems have grown popular as comfort ventilation in rooms with thermal loads e.g. offices....

  5. Design guidelines for natural ventilation systems in tertiary sector buildings

    OpenAIRE

    Van Moeseke, Geoffrey; Bruyère, Isabelle; De Herde, André; CISBAT 2005: Renewables in a changing climate

    2005-01-01

    Parameters determining efficiency of natural ventilation systems are numerous. The most important are architecture and system design. This article get onto both but focuses on system design. Through dynamic simulations it shows that natural ventilation management has a large impact on energy saving but most of all on thermal comfort. Natural ventilation techniques are also weighted against hybrid solutions and high efficiency mechanical cooling solutions. Natural ventilation techniques show t...

  6. The Comparison Effects of Two Methods of (Adaptive Support Ventilation Minute Ventilation: 110% and Adaptive Support Ventilation Minute Ventilation: 120% on Mechanical Ventilation and Hemodynamic Changes and Length of being in Recovery in Intensive Care Units

    Directory of Open Access Journals (Sweden)

    Babak Ali Kiaei

    2017-01-01

    Full Text Available Background: The conventional method for ventilation is supported by accommodative or adaptive support ventilation (ASV that the latter method is done with two methods: ASV minute ventilation (mv: 110% and ASV mv: 120%. Regarding these methods this study compared the differences in duration of mechanical ventilation and hemodynamic changes during recovery and length of stay in Intensive Care Units (ICU. Materials and Methods: In a clinical trial study, forty patients candidate for ventilation were selected and randomly divided into two groups of A and B. All patients were ventilated by Rafael ventilator. Ventilator parameters were set on ASV mv: 110% or ASV mv: 120% and patients were monitored on pulse oximetry, electrocardiography monitoring, central vein pressure and arterial pressure. Finally, the data entered to computer and analyzed by SPSS software. Results: The time average of connection to ventilator in two groups in modes of ASV mv: 110% and 120% was 12.3 ± 3.66 and 10.8 ± 2.07 days respectively, and according to t-test, there was no significant difference between two groups (P = 0.11. The average of length of stay in ICU in two groups of 110% and 120% was 16.35 ± 3.51 and 15.5 ± 2.62 days respectively, and according to t-test, there found to be no significant difference between two groups (P = 0.41. Conclusion: Using ASV mv: 120% can decrease extubation time compared with ASV mv: 110%. Furthermore, there is not a considerable side effect on hemodynamic of patients.

  7. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intermittent mandatory ventilation attachment. 868... SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5955 Intermittent mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV) attachment...

  8. 21 CFR 888.4230 - Cement ventilation tube.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device usually made of plastic intended to be inserted into...

  9. Intelligent ventilation in the intensive care unit | Sviri | Southern ...

    African Journals Online (AJOL)

    During the study period, 1 220 patients were ventilated in the MICU. Most patients (84%) were ventilated with ASV on admission. The median duration of ventilation with ASV was 6 days. The weaning success rate was 81%, and tracheostomy was required in 13%. Sixty-eight patients (6%) with severe hypoxia and high ...

  10. Experimental Analysis and Model Validation of an Opaque Ventilated Facade

    DEFF Research Database (Denmark)

    López, F. Peci; Jensen, Rasmus Lund; Heiselberg, Per

    2012-01-01

    Natural ventilation is a convenient way of reducing energy consumption in buildings. In this study an experimental module of an opaque ventilated façade (OVF) was built and tested for assessing its potential of supplying free ventilation and air preheating for the building. A numerical model was ...

  11. 46 CFR 78.47-53 - Automatic ventilation dampers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Automatic ventilation dampers. 78.47-53 Section 78.47-53... Fire and Emergency Equipment, Etc. § 78.47-53 Automatic ventilation dampers. (a) The manual operating positions for automatic fire dampers in ventilation ducts passing through main vertical zone bulkheads shall...

  12. Hybrid Ventilation in New and Retrofitted Office Buildings

    DEFF Research Database (Denmark)

    Heiselberg, Per

    The scope of this annex is to obtain better knowledge of the use of hybrid ventilation technologies. The annex will focus on development of control strategies for hybrid ventilation, on development of methods to predict hybrid ventilation performance in office buildings and on development...

  13. 33 CFR 183.630 - Standards for natural ventilation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Standards for natural ventilation... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.630 Standards for natural ventilation. (a) For the purpose of § 183.620, “natural ventilation” means an airflow in a compartment in a...

  14. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Science.gov (United States)

    2010-10-01

    ... section is satisfied, a vessel having only a natural ventilation system must satisfy the following: V/A≥1... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation (other than machinery spaces). 169.315... SCHOOL VESSELS Construction and Arrangement Hull Structure § 169.315 Ventilation (other than machinery...

  15. Biphasic cuirass ventilation is better than bag-valve mask ventilation for resuscitation following organophosphate poisoning

    Directory of Open Access Journals (Sweden)

    Ilan Gur

    2015-01-01

    Conclusions: The noninvasive, easy-to-operate Biphasic Cuirass Ventilation device was effective in reducing OP-induced mortality and might be advantageous in an organophosphate mass casualty event. This finding should be validated in further investigations.

  16. Ventilation in medium-sized and large boiler houses; Ventilation i medelstora och stoerre pannhus

    Energy Technology Data Exchange (ETDEWEB)

    Grotherus, Dan [AaF Installation AB, Oerebro (Sweden); Larsson, Tord [Oerebro Univ. (Sweden). Dept. of Technology

    2005-04-01

    The purpose of this report is to exemplify and clarify the need for ventilation in medium-sized and large boiler houses. We will furthermore present some recommendations, guidelines and advice for the design and construction of a boiler house ventilation system to the plant owners and suppliers of equipment. Boiler house ventilation can be performed in different ways using mechanical or natural ventilation. The solution to be chosen depends on the following factors: Working environment requirements and a necessity to control temperature and pressure in the boiler house; The design of the boiler plant and house; The need for combustion air; The investment expenditure as well as operation and maintenance costs. Mechanical ventilation should be chosen if the aim is a controllable 'climate'. The mechanical ventilation can be either centrally situated or distributed with many aggregates in the boiler house. Centrally situated ventilation equipment will give a higher accessibility and lower maintenance costs than a distributed ventilation system. If the boiler house is designed with natural ventilation the air and flue gas fans will be the only ones installed. In this case temperature and pressure inside the boiler house will be difficult to control. The design factor for the ventilation plant in a boiler house is in most cases the demand to cool the air inside the boiler house to approximately 45 deg C. This is the highest temperature allowed by the Occupational Safety and Health Act in a work environment where the boiler operator is working alone. The air flow which is required for the combustion is normally less than the air flow needed to cool the air in the boiler house. The supply air which is cooling the air inside the boiler house should be supplied on several different levels to attain an efficient cooling. If the combustion air is taken from the heated indoor air the boiler house will work as a heat reclaimer. The difference between outdoor and indoor

  17. Improve train tunnel. A dynamical ventilation method

    NARCIS (Netherlands)

    Phaff, J.C.; Gids, W.F. de

    1996-01-01

    Train tunnels and subways are an interesting field of ventilation. Trains move air through tunnels at rates of 600 m3/s (over 2 x 106 m3 per hour) which is much more than flow rates in buildings. Air pressures can vary up to some 3000 Pa leading to air velocities in the range of 10 to 50 m/s. This

  18. Indirect Calorimetry in Mechanically Ventilated Patients

    DEFF Research Database (Denmark)

    Allingstrup, Matilde Jo; Kondrup, Jens; Perner, Anders

    2017-01-01

    Background and Aims: The 2 currently available indirect calorimeters, CCM Express Indirect Calorimeter (MedGraphics, St Paul, MN) and Quark RMR ICU Indirect Calorimeter (COSMED, Rome, Italy), have not been validated against a gold standard in mechanically ventilated patients. Our aim was to do so...

  19. Enhanced natural ventilation method for atrium space

    NARCIS (Netherlands)

    An, H.

    2011-01-01

    This paper is written for the TIDO-course AR0532 Smart & Bioclimatic Design Theory. Energy saving is a relevant issue nowadays. Heating, ventilation and air conditioning (HVAC) occupies the largest portion both in residential and non-residential field. This consumption goes with the demand for

  20. Improving underground ventilation conditions in coal mines

    CSIR Research Space (South Africa)

    Meyer, CF

    1993-11-01

    Full Text Available The aim of this project was to establish the needs of the industry with regard to bord and pillar ventilation requirements. In addition, the aim was to establish whether sufficient research has already been done by the mining industry and if further...

  1. Climate sensitivity of the Antarctic ventilation

    Science.gov (United States)

    Ito, T.; Lynch-Stieglitz, J.

    2014-12-01

    Simple box models of ocean-atmosphere carbon cycle predict that Antarctic ventilation can regulate the steady-state atmospheric CO2 through its control over the biological carbon storage in the deep ocean. A weakened upwelling would lead to a more complete nutrient utilization at the surface and an increased retention of biogenic carbon in the deep ocean. We perform a suite of numerical sensitivity experiments using a coupled seaice and global ocean circulation model to better understand what regulates the Antarctic ventilation and its link to glacial climate. The model is first spun up with a modern climatological surface forcing, which exhibits a multi-decadal oscillation, where the Southern Ocean is heated from below through the influx of warm and salty North Atlantic Deep Water, and the accumulation of heat induces intermittent convective overturning. Through the sensitivity experiments, we explore and illustrate the rich and complex behavior of the Antarctic ventilation and its response to the northern sinking, the surface wind stress, and the global mean temperature. When the northern sinking is weakened by a freshwater perturbation, the intermittent convection events are suppressed as the heat source is reduced. When the atmospheric temperature is lowered uniformly, the Antarctic seaice extent increases and the southern overturning weakens on centennial timescales. However, the convective overturning rebounds on the millennial timescale if the northern sinking is active. We will discuss implications of our results to the deep ventilation of the Southern Ocean and its impact on the ocean carbon storage.

  2. Psychosocial problems arising from home ventilation

    NARCIS (Netherlands)

    van Kesteren, RG; Velthuis, B; van Leyden, LW

    Objective: To study psychosocial questions and problems of patients, who are chronically dependent on artificial ventilation, and their families. Design: A total of 38 patients and family members (n = 43) were randomly selected. Several patients (n = 12) received respiratory support by nasal mask;

  3. Modelling ventilated bulk storage of agromaterials

    NARCIS (Netherlands)

    Grubben, N.L.M.; Keesman, K.J.

    2015-01-01

    Storage of season-dependent agro-materials is a key process in providing food, feed and biomass throughout the whole year. We review the state of the art in physical modelling, simulation and control of ventilated bulk storage facilities, and in particular the storage of potatoes, from a

  4. A computerized aid in ventilating neonates

    DEFF Research Database (Denmark)

    Arrøe, M

    1991-01-01

    and contains a continuous evaluation of the last six values of pCO2 and pO2 resulting in statements and warnings in potentially harmful situations. The program is consistent with the written instructions of the department. The ventilator treatment of 30 premature babies is evaluated retrospectively using...

  5. Sensory source strength of used ventilation filters

    DEFF Research Database (Denmark)

    Clausen, Geo; Alm, Ole Martin; Fanger, Povl Ole

    2002-01-01

    A two-year-old filter was placed in a ventilation system recirculating the air in an experimental space. Via glass tubes supplied with a small fan it was possible to extract air upstream and downstream of the filter to an adjacent room. A panel could thus perform sensory assessments of the air fr...

  6. Displacement Ventilation by Different Types of Diffusers

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Hoff, Lars; Pedersen, Lars Germann

    The paper describes measuring results of the air movement from three different types of diffusers for displacement ventilation. Two of the diffusers are lowlevel wall mounted diffusers, one with a low and one with a high initial entrainment. The third diffuser is of the floor mounted type....

  7. Physiological Effects of Positive Pressure Ventilation.

    Science.gov (United States)

    1992-05-01

    treated by mechanical ventilatory support.. This paper presents the more common forms of mechanical ventilatory support with the adjuncts of PEEP and CPAP ...44 Researcher .......... .............. 46 Consultant . .............. 49 Educator .......... ............... 51 Manager...similar to continuous positive pressure ventilation ( CPAP ) except that PEEP pressure is maintained at end-expiration only and CPAP is maintained

  8. Ventilator associated pneumonia and infection control

    NARCIS (Netherlands)

    Alp, E.; Voss, A.

    2006-01-01

    Ventilator associated pneumonia (VAP) is the leading cause of morbidity and mortality in intensive care units. The incidence of VAP varies from 7% to 70% in different studies and the mortality rates are 20-75% according to the study population. Aspiration of colonized pathogenic microorganisms on

  9. [Percutaneous tracheostomy in the ventilated patient].

    Science.gov (United States)

    Añón, J M; Araujo, J B; Escuela, M P; González-Higueras, E

    2014-04-01

    The medical indications of tracheostomy comprise the alleviation of upper airway obstruction; the prevention of laryngeal and upper airway damage due to prolonged translaryngeal intubation in patients subjected to prolonged mechanical ventilation; and the facilitation of airway access for the removal of secretions. Since 1985, percutaneous tracheostomy (PT) has gained widespread acceptance as a method for creating a surgical airway in patients requiring long-term mechanical ventilation. Since then, several comparative trials of PT and surgical tracheostomy have been conducted, and new techniques for PT have been developed. The use of percutaneous dilatation techniques under bronchoscopic control are now increasingly popular throughout the world. Tracheostomy should be performed as soon as the need for prolonged intubation is identified. However a validated model for the prediction of prolonged mechanical ventilation is not available, and the timing of tracheostomy should be individualized. The present review analyzes the state of the art of PT in mechanically ventilated patients--this being regarded by many as the technique of choice in performing tracheostomy in critically ill patients. Copyright © 2012 Elsevier España, S.L. and SEMICYUC. All rights reserved.

  10. A Medical Student Workshop in Mechanical Ventilation.

    Science.gov (United States)

    And Others; Kushins, Lawrence G.

    1980-01-01

    In order to teach applied respiratory physiology to medical students, the anesthesiology faculty at the University of Florida College of Medicine has designed and implemented a course that includes a laboratory workshop in mechanical ventilation of an animal model that allows students to apply and expand their knowledge. (JMD)

  11. Diaphragm Dysfunction in Mechanically Ventilated Patients.

    Science.gov (United States)

    Dot, Irene; Pérez-Teran, Purificación; Samper, Manuel-Andrés; Masclans, Joan-Ramon

    2017-03-01

    Muscle involvement is found in most critical patients admitted to the intensive care unit (ICU). Diaphragmatic muscle alteration, initially included in this category, has been differentiated in recent years, and a specific type of muscular dysfunction has been shown to occur in patients undergoing mechanical ventilation. We found this muscle dysfunction to appear in this subgroup of patients shortly after the start of mechanical ventilation, observing it to be mainly associated with certain control modes, and also with sepsis and/or multi-organ failure. Although the specific etiology of process is unknown, the muscle presents oxidative stress and mitochondrial changes. These cause changes in protein turnover, resulting in atrophy and impaired contractility, and leading to impaired functionality. The term 'ventilator-induced diaphragm dysfunction' was first coined by Vassilakopoulos et al. in 2004, and this phenomenon, along with injury cause by over-distention of the lung and barotrauma, represents a challenge in the daily life of ventilated patients. Diaphragmatic dysfunction affects prognosis by delaying extubation, prolonging hospital stay, and impairing the quality of life of these patients in the years following hospital discharge. Ultrasound, a non-invasive technique that is readily available in most ICUs, could be used to diagnose this condition promptly, thus preventing delays in starting rehabilitation and positively influencing prognosis in these patients. Copyright © 2016 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Survival after Pneumocystis jirovecii pneumonia requiring ventilation ...

    African Journals Online (AJOL)

    Pneumocystis pneumonia (PCP) in patients with the human immunodeficiency virus (HIV) is associated with a high mortality rate, which increases substantially with the need for mechanical ventilation. Local experience of patients with PCP admitted to the intensive care unit has revealed mortality rates close to 100%.

  13. Implementation of ventilation in existing schools

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Petersen, Steffen

    ; they evaluate both scientific and practical implementation The analyses lead to a list of criteria associated with the implementation of ventilation in existing schools. Generic retrofitting scenarios which prioritize energy savings, indoor climate and building/facade integration are assembled and illustrated...

  14. 46 CFR 194.15-5 - Ventilation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194...

  15. Interfaces and ventilator settings for long-term noninvasive ventilation in COPD patients

    Directory of Open Access Journals (Sweden)

    Callegari J

    2017-06-01

    Full Text Available Jens Callegari,1 Friederike Sophie Magnet,1 Steven Taubner,1 Melanie Berger,2 Sarah Bettina Schwarz,1 Wolfram Windisch,1 Jan Hendrik Storre3,4 1Department of Pneumology, Cologne-Merheim Hospital, Kliniken der Stadt Koeln, Witten/Herdecke University Hospital, 2Department of Pneumology, Malteser Hospital St Hildegardis, Cologne, 3Department of Pneumology, University Medical Hospital, Freiburg, 4Department of Intensive Care, Sleep Medicine and Mechanical Ventilation, Asklepios Fachkliniken Munich-Gauting, Gauting, Germany Introduction: The establishment of high-intensity (HI noninvasive ventilation (NIV that targets elevated PaCO2 has led to an increase in the use of long-term NIV to treat patients with chronic hypercapnic COPD. However, the role of the ventilation interface, especially in more aggressive ventilation strategies, has not been systematically assessed.Methods: Ventilator settings and NIV compliance were assessed in this prospective cross-sectional monocentric cohort study of COPD patients with pre-existing NIV. Daytime ­arterialized blood gas analyses and lung function testing were also performed. The primary end point was the distribution among study patients of interfaces (full-face masks [FFMs] vs nasal masks [NMs] in a real-life setting.Results: The majority of the 123 patients studied used an FFM (77%, while 23% used an NM. Ventilation settings were as follows: mean ± standard deviation (SD inspiratory positive airway pressure (IPAP was 23.2±4.6 mbar and mean ± SD breathing rate was 16.7±2.4/minute. Pressure support ventilation (PSV mode was used in 52.8% of patients, while assisted pressure-controlled ventilation (aPCV was used in 47.2% of patients. Higher IPAP levels were associated with an increased use of FFMs (IPAP <21 mbar: 73% vs IPAP >25 mbar: 84%. Mean compliance was 6.5 hours/day, with no differences between FFM (6.4 hours/day and NM (6.7 hours/day users. PaCO2 assessment of ventilation quality revealed

  16. Biologically variable ventilation improves oxygenation and respiratory mechanics during one-lung ventilation.

    Science.gov (United States)

    McMullen, Michael C; Girling, Linda G; Graham, M Ruth; Mutch, W Alan C

    2006-07-01

    Hypoxemia is common during one-lung ventilation (OLV). Atelectasis contributes to the problem. Biologically variable ventilation (BVV), using microprocessors to reinstitute physiologic variability to respiratory rate and tidal volume, has been shown to be advantageous over conventional monotonous control mode ventilation (CMV) in improving oxygenation during the period of lung reinflation after OLV in an experimental model. Here, using a porcine model, the authors compared BVV with CMV during OLV to assess gas exchange and respiratory mechanics. Eight pigs (25-30 kg) were studied in each of two groups. After induction of anesthesia-tidal volume 12 ml/kg with CMV and surgical intervention-tidal volume was reduced to 9 ml/kg. OLV was initiated with an endobronchial blocker, and the animals were randomly allocated to either continue CMV or switch to BVV for 90 min. After OLV, a recruitment maneuver was undertaken, and both lungs were ventilated for a further 60 min. At predetermined intervals, hemodynamics, respiratory gases (arterial, venous, and end-tidal samples) and mechanics (airway pressures, static and dynamic compliances) were measured. Derived indices (pulmonary vascular resistance, shunt fraction, and dead space ventilation) were calculated. By 15 min of OLV, arterial oxygen tension was greater in the BVV group (group x time interaction, P = 0.003), and shunt fraction was lower with BVV from 30 to 90 min (group effect, P = 0.0004). From 60 to 90 min, arterial carbon dioxide tension was lower with BVV (group x time interaction, P = 0.0001) and dead space ventilation was less from 60 to 90 min (group x time interaction, P = 0.0001). Static compliance was greater by 60 min of BVV and remained greater during return to ventilation of both lungs (group effect, P = 0.0001). In this model of OLV, BVV resulted in superior gas exchange and respiratory mechanics when compared with CMV. Improved static compliance persisted with restoration of two-lung ventilation.

  17. A RESEARCH ON VENTILATION EFFICIENCY OF PIPED VENTILATION SYSTEMS IN GEOTHERMALLY HEATED GREENHOUSES

    Directory of Open Access Journals (Sweden)

    İbrahim Örüng

    2016-07-01

    Full Text Available Greenhouse play significant roles in human nutrition. Vegetable and fruit consumption at certain amounts is the basic pre-condition for a well nutrition. It is possible to produce sufficient quantities of fruits and vegetables in places with available climate conditions. However, fruits and vegetables should be grown in special buildings to have a year-long production in places without available climate conditions. These places include under-cover production facilities, greenhouses, low and high tunnel facilities. Environmental conditions are adjusted are adjusted in greenhouses as to provide proper conditions for plant growth and development. Ventilation is used to remove excess heat, moisture and carbon dioxide from the greenhouses. Either natural or mechanical ventilation is used in greenhouses. Mechanical ventilation systems have various advantages over natural systems. However, mostly natural ventilation systems are preferred because of their low installation and operational costs. Both systems operates based on negative pressure. Air exchange rates are usually low in winters and it is quite hard to evenly distribute cold fresh air within the greenhouse. Air inlets are usually placed over side walls and outlets are commonly placed along the ridge. In this study an alternative natural ventilation system was proposed for more efficient ventilation of the greenhouses. In this system, fresh air gets into the greenhouse through ventilation pipes installed beneath the greenhouse floor. The incoming fresh air also heated with geothermal hot water lines, thus direct contact of cold fresh air is prevented. The design and efficiency of piped ventilation systems were provided in this paper.

  18. Mechanical ventilation in the newborn; a simplified approach. Part 2: High-frequency ventilation.

    Science.gov (United States)

    Muhlethaler, Vincent; Malcolm, Girvan

    2014-10-01

    High frequency oscillatory ventilation (HFOV) is becoming an increasingly popular intervention in the neonatal intensive care unit. This article will attempt to explain the principles of HFOV. It is inherently more difficult to become skilled in this technique than in other forms of mechanical ventilation, so caution is warranted. © 2010 The Author. Journal of Paediatrics and Child Health © 2010 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  19. Effective, industrial ventilation systems. New generation of ventilation systems under development; Effectieve, industriele ventilatiesystemen

    Energy Technology Data Exchange (ETDEWEB)

    Moons, A.; Knoll, B. [TNO Bouw en Ondergrond, Delft (Netherlands)

    2008-02-15

    Industrial processes and tools can expose employees to various harmful substances. This is a burden that often takes place decentralized. Room ventilation alone usually does not offer enough protection. New ventilation concepts can offer employees effective protection. (mk) [Dutch] Industriele processen en gereedschappen kunnen werknemers blootstellen aan allerlei schadelijke stoffen. Een belasting die vaak zeer decentraal plaatsheeft. Alleen ruimteventilatie biedt doorgaans onvoldoende bescherming. Nieuwe ventilatieconcepten kunnen medewerkers wel een effectieve bescherming bieden.

  20. Ventrain: an ejector ventilator for emergency use.

    Science.gov (United States)

    Hamaekers, A E W; Borg, P A J; Enk, D

    2012-06-01

    A small, flow-regulated, manually operated ventilator designed for ventilation through a narrow-bore transtracheal catheter (TTC) has become available (Ventrain, Dolphys Medical BV, Eindhoven, The Netherlands). It is driven by a predetermined flow of oxygen from a high-pressure source and facilitates expiration by suction. The aim of this bench study was to test the efficacy of this new ventilator. The driving pressure, generated insufflation, and suction pressures and also the suction capacity of the Ventrain were measured at different oxygen flows. The minute volume achieved in an artificial lung through a TTC with an inner diameter (ID) of 2 mm was determined at different settings. Oxygen flows of 6-15 litre min(-1) resulted in driving pressures of 0.5-2.3 bar. Insufflation pressures, measured proximal to the TTC, ranged from 23 to 138 cm H(2)O. The maximal subatmospheric pressure build-up was -217 cm H(2)O. The suction capacity increased to a maximum of 12.4 litre min(-1) at an oxygen flow of 15 litre min(-1). At this flow, the achievable minute volume through the TTC ranged from 5.9 to 7.1 litres depending on the compliance of the artificial lung. The results of this bench study suggest that the Ventrain is capable of achieving a normal minute volume for an average adult through a 2 mm ID TTC. Further in vivo studies are needed to determine the value of the Ventrain as a portable emergency ventilator in a 'cannot intubate, cannot ventilate' situation.

  1. Mechanical ventilation and house-dust mites. Mekanisk ventilation og husstoevmider

    Energy Technology Data Exchange (ETDEWEB)

    Korsgaard, J. (Lungeklinikken, Aarhus Kommunehospital, Aarhus (DK))

    1991-01-01

    Nationally and internationally, it is recognised that the rational way to reduce inhabitant exposure to house-dust meters in a temperate climate is to reduce indoor absolute humidity to a level below 7.0 g/kg in the dry winter period. Consequently, it is medically recommended to install mechanical ventilation as environmental treatment of patients with chronic asthma caused by indoor exposure to house-dust mites. In this controlled investigation on the effect of mechanical ventilation on indoor climate conditions, it is documented that the establishment of a basic ventilation rate of 0.5 ach implies a significant reduction in the occurrence of house-dust mites in dwellings. Parallel with this effect, the rate of inside condensation on double-glazed windows was reduced, and the reported complaint rate of humid air, stuffy and dustry air and the indoor smelling sensation were reduced by a factor 2 to 7. No side effects relating to ventilation equipment were reported. It is conclued that the installation of mechanical ventilation in the treatment of mite allergy should be individualized with recommended air exchange rates adjusted to the actual size of dwelling and number of inhabitants. Furthermore care should be taken to avoid risk of condensation in the ventilation equipment. (author).

  2. The cost of ventilation in birds measured via unidirectional artificial ventilation.

    Science.gov (United States)

    Markley, Jessamyn S; Carrier, David R

    2010-02-01

    The highly derived mechanism birds use to ventilate their lungs relies on dorsoventral excursions of their heavily muscled sternum and abdominal viscera. Our expectation of the level of mechanical work involved in this mechanism led us to hypothesize that the metabolic cost of breathing is higher in birds than in other tetrapods. To test this theory, we used unidirectional artificial ventilation (UDV) to stop normal ventilatory movements in guinea fowl (Numida meleagris L.) at rest and during treadmill locomotion at three speeds. Oxygen consumption was measured during normal breathing and UDV, and the difference was used to approximate the cost of ventilation. Contrary to our prediction, metabolism increased when ventilatory movements ceased during UDV at rest. Although we do not understand why this occurred we suspect that UDV induced a homeostatic mechanism to counteract the loss of carbon dioxide. Nevertheless, across all running speeds, metabolism decreased significantly with UDV, indicating a minimum cost of ventilation during running of 1.43+/-0.62% of total running metabolism or 0.48+/-0.21 mL O(2) (L ventilated)(-1). These results suggest that the metabolic cost of ventilation is low in birds and that it is within the range of costs reported previously for other amniotes. Elsevier Inc.

  3. Changes in lung volume and ventilation during lung recruitment in high-frequency ventilated preterm infants with respiratory distress syndrome

    NARCIS (Netherlands)

    Miedema, Martijn; de Jongh, Frans H.; Frerichs, Inez; van Veenendaal, Mariëtte B.; van Kaam, Anton H.

    2011-01-01

    To assess global and regional changes in lung volume and ventilation during lung recruitment in preterm infants with respiratory distress syndrome. Using electrical impedance tomography, changes in lung volume and ventilation were measured in 15 high-frequency oscillatory ventilated preterm infants

  4. SY Tank Farm ventilation isolation option risk assessment report

    Energy Technology Data Exchange (ETDEWEB)

    Powers, T.B.; Morales, S.D.

    1994-03-01

    The safety of the 241-SY Tank Farm ventilation system has been under extensive scrutiny due to safety concerns associated with tank 101-SY. Hydrogen and other gases are generated and trapped in the waste below the liquid surface. Periodically, these gases are released into the dome space and vented through the exhaust system. This attention to the ventilation system has resulted in the development of several alternative ventilation system designs. The ventilation system provides the primary means of mitigation of accidents associated with flammable gases. This report provides an assessment of various alternatives ventilation system designs.

  5. Modeling and Control of Livestock Ventilation Systems and Indoor Environments

    DEFF Research Database (Denmark)

    Wu, Zhuang; Heiselberg, Per; Stoustrup, Jakob

    2005-01-01

    The hybrid ventilation systems have been widely used for livestock barns to provide optimum indoor climate by controlling the ventilation rate and air flow distribution within the ventilated building structure. The purpose of this paper is to develop models for livestock ventilation systems and i...... constraints and random disturbances is designed through system linearization. The well designed control systems are able to determine the demand ventilation rate and airflow pattern, improve and optimize the indoor Thermal Comfort (TC), Indoor Air Quality (IAQ) and energy use....

  6. Emergency Department Blood Gas Utilization and Changes in Ventilator Settings.

    Science.gov (United States)

    Al Ashry, Haitham S; Richards, Jeremy B; Fisher, Daniel F; Sankoff, Jeffrey; Seigel, Todd A; Angotti, Lauren B; Wilcox, Susan R

    2017-09-26

    Mechanically ventilated patients increasingly spend hours in emergency department beds before ICU admission. This study evaluated the performance of blood gases in mechanically ventilated subjects in the emergency department and subsequent changes to mechanical ventilation settings. This was a multi-center, prospective, observational study of subjects ventilated in the emergency department, conducted at 3 academic emergency departments from July 2011 to March 2013. We measured the rate of arterial blood gas (ABG) and venous blood gas (VBG) analysis, and we assessed the associations between the conditions of hypoxemia, hyperoxia, hypercapnia, or acidemia and changes to mechanical ventilator settings. Of 292 ventilated subjects, 17.1% did not have a blood gas sent in the emergency department. Ventilator changes were made significantly more frequently for subjects who had an ABG as the initial blood gas sent in the emergency department (odds ratio 2.70, 95% CI 1.46-4.99, P = .002). However, findings of hypoxemia, hyperoxia, hypercapnia, or acidemia were not correlated with ventilator adjustments. In this prospective observational study of subjects mechanically ventilated in the emergency department, the majority had a blood gas checked while in the emergency department. While ABGs were associated with having changes made to ventilator settings in the emergency department, clinical findings of hypoxemia, hyperoxia, hypercapnia, and acidemia were not. Inattention to blood gas results may lead to missed opportunities in guiding ventilator changes in the emergency department. Copyright © 2017 by Daedalus Enterprises.

  7. Characterization of pediatric patients receiving prolonged mechanical ventilation.

    Science.gov (United States)

    Monteverde, Ezequiel; Fernández, Analía; Poterala, Rossana; Vidal, Nilda; Siaba Serrate, Alejandro; Castelani, Pablo; Albano, Lidia; Podestá, Fernanda; Farias, Julio A

    2011-11-01

    To describe the characteristics and risk factors of pediatric patients who receive prolonged mechanical ventilation, defined as ventilatory support for >21 days. Prospective cohort. Four medical-surgical pediatric intensive care units in four university-affiliated hospitals in Argentina. All consecutive patients from 1 month to 15 yrs old admitted to participating pediatric intensive care units from June 1, 2007, to August 31, 2007, who received mechanical ventilation (invasive or noninvasive) for >12 hrs. None. Demographic and physiologic data on admission to the pediatric intensive care units, drugs and events during the study period, and outcomes were prospectively recorded. A total of 256 patients were included. Of these, 23 (9%) required mechanical ventilation for >21 days and were assigned to the prolonged mechanical ventilation group. Patients requiring prolonged mechanical ventilation had higher mortality (43% vs. 21%, p mechanical ventilation patients (26% vs. 9%, p ventilator-associated pneumonia (35% vs. 8%, p mechanical ventilation group with similar rates of unplanned extubations in both groups. Variables remaining significantly associated with prolonged mechanical ventilation after multivariate analysis were treatment with multiple antibiotics, septic shock, ventilator-associated pneumonia, and use of norepinephrine. Patients with prolonged mechanical ventilation have more complications and require more pediatric intensive care unit resources. Mortality in these patients duplicates that from those requiring shorter support.

  8. Instrument Modeling and Synthesis

    Science.gov (United States)

    Horner, Andrew B.; Beauchamp, James W.

    During the 1970s and 1980s, before synthesizers based on direct sampling of musical sounds became popular, replicating musical instruments using frequency modulation (FM) or wavetable synthesis was one of the “holy grails” of music synthesis. Synthesizers such as the Yamaha DX7 allowed users great flexibility in mixing and matching sounds, but were notoriously difficult to coerce into producing sounds like those of a given instrument. Instrument design wizards practiced the mysteries of FM instrument design.

  9. Perceived Air Quality in a Displacement Ventilated Room

    DEFF Research Database (Denmark)

    Brohus, Henrik; Knudsen, Henrik Nellemose; Nielsen, Peter V.

    In a displacement ventilated room the non-uniform contaminant distribution causes an improved indoor air quality in the occupied zone compared with conventional mixing ventilation. This has been demonstrated in numerous studies by chemical measurements. In this study the air quality in a displace......In a displacement ventilated room the non-uniform contaminant distribution causes an improved indoor air quality in the occupied zone compared with conventional mixing ventilation. This has been demonstrated in numerous studies by chemical measurements. In this study the air quality...... in a displacement ventilated room was determined directly by asking humans about how they perceived the air quality. A trained sensory panel comprising 12 subjects assessed the perceived air quality immediately after entering a climate chamber. The experiments showed that the perceived air quality...... in the displacement ventilated chamber was substantially better than in the case of mixing ventilation....

  10. The Instrumental Model

    Science.gov (United States)

    Yeates, Devin Rodney

    2011-01-01

    The goal of this dissertation is to enable better predictive models by engaging raw experimental data through the Instrumental Model. The Instrumental Model captures the protocols and procedures of experimental data analysis. The approach is formalized by encoding the Instrumental Model in an XML record. Decoupling the raw experimental data from…

  11. Aeroacoustics of Musical Instruments

    NARCIS (Netherlands)

    Fabre, B.; Gilbert, J.; Hirschberg, Abraham; Pelorson, X.

    2012-01-01

    We are interested in the quality of sound produced by musical instruments and their playability. In wind instruments, a hydrodynamic source of sound is coupled to an acoustic resonator. Linear acoustics can predict the pitch of an instrument. This can significantly reduce the trial-and-error process

  12. [Organization of mechanical ventilation in French Intensive care units].

    Science.gov (United States)

    Montravers, P; Ichai, C; Dupont, H; Payen, J F; Orliaguet, G; Blanchet, P; Malledant, Y; Albanèse, J; Asehnoune, K; Bastien, O; Collange, O; Duranteau, J; Garrigues, B; Lepape, A; Paugam-Burtz, C

    2013-11-01

    To clarify the procedures related to mechanical ventilation in the intensive care unit setting: allocation of ventilators, team education, maintenance and reference documents. Declarative survey. Between September and December 2010, we assessed the assignment and types of ventilators (ICU ventilators, temporary repair ventilators, non-invasive ventilators [NIV], and transportation ventilators), medical and nurse education, maintenance of the ventilators, presence of reference documents. Results are expressed in median/range and proportions. Among the 62 participating ICUs, a median of 15 ventilators/ICU (range 1-50) was reported with more than one trademark in 47 (76%) units. Specific ventilators were used for NIV in 22 (35%) units, temporary repair in 49 (79%) and transportation in all the units. Nurse education courses were given by ICU physicians in 54 (87%) units or by a company in 29 (47%) units. Medical education courses were made by ICU senior physicians in 55 (89%) units or by a company in 21 (34%) units. These courses were organized occasionally in 24 (39%) ICU and bi-annually in 16 (26%) units. Maintenance procedures were made by the ICU staff in 39 (63%) units, dedicated staff (17 [27%]) or bioengineering technicians (14 [23%] ICU). Reference documents were written for maintenance procedures in 48 (77%) units, ventilator setup in 22 (35%) units and ventilator dysfunction in 20 (32%) ICU. This first survey shows disparate distribution of ventilators and practices among French ICU. Education and understanding of the proper use of ventilators are key issues for security improvement. Copyright © 2013 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  13. One-lung ventilation induces hyperperfusion and alveolar damage in the ventilated lung: an experimental study.

    Science.gov (United States)

    Kozian, A; Schilling, T; Fredén, F; Maripuu, E; Röcken, C; Strang, C; Hachenberg, T; Hedenstierna, G

    2008-04-01

    One-lung ventilation (OLV) increases mechanical stress in the lung and affects ventilation and perfusion (V, Q). There are no data on the effects of OLV on postoperative V/Q matching. Thus, this controlled study evaluates the influence of OLV on V/Q distribution in a pig model using a gamma camera technique [single-photon emission computed tomography (SPECT)] and relates these findings to lung histopathology after OLV. Eleven anaesthetized and ventilated pigs (V(T)=10 ml kg(-1), Fio2=0.40, PEEP=5 cm H2O) were studied. After lung separation, OLV and thoracotomy were performed in seven pigs (OLV group). During OLV and in a two-lung ventilation (TLV), control group (n=4) ventilation settings remained unchanged. SPECT with (81m)Kr (ventilation) and (99m)Tc-labelled macro-aggregated albumin (perfusion) was performed before, during, and 90 min after OLV/TLV. Finally, lung tissue samples were harvested and examined for alveolar damage. OLV affected ventilation and haemodynamic variables, but there were no differences between the OLV group and the control group before and after OLV/TLV. SPECT revealed an increase of perfusion in the dependent lung compared with baseline (49-56%), and a corresponding reduction of perfusion (51-44%) in non-dependent lungs after OLV. No perfusion changes were observed in the control group. This resulted in increased low V/Q regions and a shift of V/Q areas to 0.3-0.5 (10(-0.5)-10(-0.3)) in dependent lungs of OLV pigs and was associated with an increased diffuse alveolar damage score. OLV in pigs results in a substantial V/Q mismatch, hyperperfusion, and alveolar damage in the dependent lung and may thus contribute to gas exchange impairment after thoracic surgery.

  14. Lung-protective mechanical ventilation does not protect against acute kidney injury in patients without lung injury at onset of mechanical ventilation

    NARCIS (Netherlands)

    Cortjens, Bart; Royakkers, Annick A. N. M.; Determann, Rogier M.; van Suijlen, Jeroen D. E.; Kamphuis, Stephan S.; Foppen, Jannetje; de Boer, Anita; Wieland, Cathrien W.; Spronk, Peter E.; Schultz, Marcus J.; Bouman, Catherine S. C.

    2012-01-01

    Introduction: Preclinical and clinical studies suggest that mechanical ventilation contributes to the development of acute kidney injury (AKI), particularly in the setting of lung-injurious ventilator strategies. Objective: To determine whether ventilator settings in critically ill patients without

  15. Buoyancy Driven Natural Ventilation through Horizontal Openings

    DEFF Research Database (Denmark)

    Heiselberg, Per; Li, Zhigang

    2009-01-01

    An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening...... and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant...... quite well with the Epstein's formula but in other cases the measured data show clear deviations from the Epstein's formula. Thus, revised formulas for natural ventilation are proposed....

  16. Buoyancy Driven Natural Ventilation through Horizontal Openings

    DEFF Research Database (Denmark)

    Heiselberg, Per

    2009-01-01

    An experimental study of the phenomenon of buoyancy driven natural ventilation through single-sided horizontal openings was performed in a full-scale laboratory test rig. The measurements were made for opening ratios L/D ranging from 0.027 to 4.455, where L and D are the length of the opening...... and the diameter of the opening, respectively. The basic nature of airflow through single-sided openings, including airflow rate, air velocity, temperature difference between the rooms and the dimensions of the horizontal openings, were measured. A bi-directional airflow rate was measured using the constant...... quite well with the Epstein's formula ratio are presented. In some cases the measured airflow rates fit quite well with the Epstein's formula but in other cases the measured data show clear deviations from the Epstein's formula. Thus, revised formulas for natural ventilation are proposed....

  17. Performing the Super Instrument

    DEFF Research Database (Denmark)

    Kallionpaa, Maria

    2016-01-01

    The genre of contemporary classical music has seen significant innovation and research related to new super, hyper, and hybrid instruments, which opens up a vast palette of expressive potential. An increasing number of composers, performers, instrument designers, engineers, and computer programmers...... have become interested in different ways of “supersizing” acoustic instruments in order to open up previously-unheard instrumental sounds. Super instruments vary a great deal but each has a transformative effect on the identity and performance practice of the performing musician. Furthermore, composers...... provides the performer extensive virtuoso capabilities in terms of instrumental range, harmony, timbre, or spatial, textural, acoustic, technical, or technological qualities. The discussion will be illustrated by a composition case study involving augmented musical instrument electromagnetic resonator...

  18. Adult ICU ventilators to provide neonatal ventilation: a lung simulator study.

    Science.gov (United States)

    Marchese, Andrew D; Chipman, Daniel; de la Oliva, Pedro; Kacmarek, Robert M

    2009-04-01

    Traditionally, specific ventilators have been manufactured to only provide neonatal mechanical ventilation. However, many of the current generation of ICU ventilators also include a neonatal mode. Using the IngMar ASL5000 lung simulator the Puritan Bennett 840, the Maquet Servo i, the Viasys AVEA, the GE Engström, the Drager Evita XL and Babylog 8000 Plus were evaluated during assisted ventilation in the pressure assist/control mode. Three lung mechanics were set: resistance 50 cmH(2)O/L/s, compliance 2 mL/cmH(2)O; resistance 100 cmH(2)O/L/s, compliance 1 mL/cmH(2)O; and resistance 150 cmH(2)O/L/s, compliance 0.5 mL/cmH(2)O. A maximum negative pressure drop of 4 and 7 cmH(2)O was achieved during simulated inspirations. Each ventilator was evaluated with PEEP 5 cmH(2)O, peak pressure 20 cmH(2)O and inspiratory time 0.3 s and with PEEP 10 cmH(2)O, peak pressure 30 cmH(2)O and inspiratory time 0.4 s. Each ventilator setting was then repeated with a leak of 0.3 L/min at a constant pressure of 5 cmH(2)O. Overall each of the 5 ICU ventilators responded faster or greater than the Babylog with respect to: pressure to trigger (except the Servo i), time to trigger (except the Evita XL), time between trigger and return of pressure to baseline, time from start of breath to 90% of peak pressure (except the Avea) and pressure time product of breath activation. Expiratory tidal volume was also greater with all ICU ventilators except the Avea. Variation in mechanics, leak, PEEP and muscular effort had little effect on these differences. All ICU ventilators tested were able to at least equal the performance of the Babylog 8000 Plus on all variables evaluated.

  19. Intrapulmonary percussive ventilation superimposed on conventional mechanical ventilation: comparison of volume controlled and pressure controlled modes.

    Science.gov (United States)

    Riffard, Guillaume; Buzenet, Julien; Guérin, Claude

    2014-07-01

    Previous bench studies suggest that dynamic hyperinflation may occur if intrapulmonary percussive ventilation (IPV) is superimposed on mechanical ventilation in volume controlled continuous mandatory ventilation (VC-CMV) mode. We tested the hypothesis that pressure controlled continuous mandatory ventilation (PC-CMV) can protect against this risk. An ICU ventilator was connected to an IPV device cone adapter that was attached to a lung model (compliance 30 mL/cm H2O, resistance 20 cm H2O/L/s). We measured inspired tidal volume (VTI) and lung pressure (Plung). Measurements were first taken with IPV off and the ICU ventilator set to VC-CMV or PC-CMV mode with a targeted VTI of 500 mL. For each mode, an inspiratory time (TI) of 0.8 or 1.5 s and PEEP 7 or 15 cm H2O were selected. The experiments were repeated with the IPV set to either 20 or 30 psi. The dependent variables were differences in VTI (ΔVTI) and Plung with IPV off or on. The effect of VC-CMV or PC-CMV mode was tested with the ICU ventilators for TI, PEEP, and IPV working pressure using repeated measures of analysis of variance. At TI 0.8 s and 20 psi, ΔVTI was significantly higher in VC-CMV than in PC-CMV. PEEP had no effect on ΔVTI. At TI 1.5 s and 20 psi and at both TI values at each psi, mode and PEEP had a significant effect on ΔVTI. With the ICU ventilators at TI 1.5 s, PEEP 7 cm H2O, and 30 psi, ΔVTI (mean ± SD) ranged from -27 ± 25 to -176 ± 6 mL in PC-CMV and from 258 ± 369 to 369 ± 16 mL in VC-CMV. The corresponding ranges were -15 ± 17 to -62 ± 68 mL in PC-CMV and 26 ± 21 to 102 ± 95 mL in VC-CMV at TI 0.8 s, PEEP 7 cm H2O, and 20 psi. Similar findings pertained to Plung. When IPV is added to mechanical ventilation, the risk of hyperinflation is greater with VC-CMV than with PC-CMV. We recommend using PC-CMV to deliver IPV and adjusting the trigger variable to avoid autotriggering. Copyright © 2014 by Daedalus Enterprises.

  20. Computational fluid dynamics in ventilation design

    CERN Document Server

    Allard, Francis; Awbi, Hazim B; Davidson, Lars; Schälin, Alois

    2007-01-01

    CFD-calculations have been rapidly developed to a powerful tool for the analysis of air pollution distribution in various spaces. However, the user of CFD-calculation should be aware of the basic principles of calculations and specifically the boundary conditions. Computational Fluid Dynamics (CFD) – in Ventilation Design models is written by a working group of highly qualified international experts representing research, consulting and design.

  1. Lung-protective perioperative mechanical ventilation

    OpenAIRE

    Hemmes, S.N.T.

    2015-01-01

    Intraoperative ventilation has the potential to cause lung injury and possibly increase risk of pulmonary complications after surgery. Use of large tidal volumes could cause overdistension of lung tissue, which can be aggravated by too high levels of positive end-expiratory pressure (PEEP). Too low levels of PEEP, though, could result in repetitive opening and closing of lung tissue. The main aim of this thesis was to investigate the effect of intraoperative use of higher levels of PEEP and r...

  2. Fractal ventilation enhances respiratory sinus arrhythmia

    Directory of Open Access Journals (Sweden)

    Girling Linda G

    2005-05-01

    Full Text Available Abstract Background Programming a mechanical ventilator with a biologically variable or fractal breathing pattern (an example of 1/f noise improves gas exchange and respiratory mechanics. Here we show that fractal ventilation increases respiratory sinus arrhythmia (RSA – a mechanism known to improve ventilation/perfusion matching. Methods Pigs were anaesthetised with propofol/ketamine, paralysed with doxacurium, and ventilated in either control mode (CV or in fractal mode (FV at baseline and then following infusion of oleic acid to result in lung injury. Results Mean RSA and mean positive RSA were nearly double with FV, both at baseline and following oleic acid. At baseline, mean RSA = 18.6 msec with CV and 36.8 msec with FV (n = 10; p = 0.043; post oleic acid, mean RSA = 11.1 msec with CV and 21.8 msec with FV (n = 9, p = 0.028; at baseline, mean positive RSA = 20.8 msec with CV and 38.1 msec with FV (p = 0.047; post oleic acid, mean positive RSA = 13.2 msec with CV and 24.4 msec with FV (p = 0.026. Heart rate variability was also greater with FV. At baseline the coefficient of variation for heart rate was 2.2% during CV and 4.0% during FV. Following oleic acid the variation was 2.1 vs. 5.6% respectively. Conclusion These findings suggest FV enhances physiological entrainment between respiratory, brain stem and cardiac nonlinear oscillators, further supporting the concept that RSA itself reflects cardiorespiratory interaction. In addition, these results provide another mechanism whereby FV may be superior to conventional CV.

  3. Prognosis of deeply comatose patients on ventilators.

    OpenAIRE

    Hung, T P; Chen, S T

    1995-01-01

    Although the concept of brain death has been widely accepted, the criteria required for making the diagnosis remain controversial. This prospective study was undertaken to examine the reliability of a set of clinical criteria adopted in Taiwan. One hundred and forty deeply comatose patients (101 men, 39 women; mean age 49.5 (SD 17.6) years) requiring ventilation were studied. Seventy three patients met the clinical criteria for brainstem death; all developed cardiac asystole (97% within seven...

  4. Fractal ventilation enhances respiratory sinus arrhythmia.

    Science.gov (United States)

    Mutch, W Alan C; Graham, M Ruth; Girling, Linda G; Brewster, John F

    2005-05-09

    Programming a mechanical ventilator with a biologically variable or fractal breathing pattern (an example of 1/f noise) improves gas exchange and respiratory mechanics. Here we show that fractal ventilation increases respiratory sinus arrhythmia (RSA) -- a mechanism known to improve ventilation/perfusion matching. Pigs were anaesthetised with propofol/ketamine, paralysed with doxacurium, and ventilated in either control mode (CV) or in fractal mode (FV) at baseline and then following infusion of oleic acid to result in lung injury. Mean RSA and mean positive RSA were nearly double with FV, both at baseline and following oleic acid. At baseline, mean RSA = 18.6 msec with CV and 36.8 msec with FV (n = 10; p = 0.043); post oleic acid, mean RSA = 11.1 msec with CV and 21.8 msec with FV (n = 9, p = 0.028); at baseline, mean positive RSA = 20.8 msec with CV and 38.1 msec with FV (p = 0.047); post oleic acid, mean positive RSA = 13.2 msec with CV and 24.4 msec with FV (p = 0.026). Heart rate variability was also greater with FV. At baseline the coefficient of variation for heart rate was 2.2% during CV and 4.0% during FV. Following oleic acid the variation was 2.1 vs. 5.6% respectively. These findings suggest FV enhances physiological entrainment between respiratory, brain stem and cardiac nonlinear oscillators, further supporting the concept that RSA itself reflects cardiorespiratory interaction. In addition, these results provide another mechanism whereby FV may be superior to conventional CV.

  5. High-Frequency Percussive Ventilation Revisited

    Science.gov (United States)

    2010-01-01

    Landstuhl Regional Medical Center, Germany; and †United States Army Institute of Surgical Research, Fort Sam Houston, Texas. The author does not have...AND ADDRESS(ES) United States Army Institute of Surgical Research, JBSA Fort Sam Houston, TX 8. PERFORMING ORGANIZATION REPORT NUMBER 9...Engl J Med 1981;305:1375–9. 25. Pillow JJ. High-frequency oscillatory ventilation: mecha- nisms of gas exchange and lung mechanics. Crit Care Med

  6. Comparison of patient-ventilator asynchrony during pressure support ventilation and proportional assist ventilation modes in surgical Intensive Care Unit: A randomized crossover study.

    Science.gov (United States)

    Gautam, Parshotam Lal; Kaur, Gaganjot; Katyal, Sunil; Gupta, Ruchi; Sandhu, Preetveen; Gautam, Nikhil

    2016-12-01

    The patient-ventilator asynchrony is almost observed in all modes of ventilation, and this asynchrony affects lung mechanics adversely resulting in deleterious outcome. Innovations and advances in ventilator technology have been trying to overcome this problem by designing newer modes of ventilation. Pressure support ventilation (PSV) is a commonly used flow-cycled mode where a constant pressure is delivered by ventilator. Proportional assist ventilation (PAV) is a new dynamic inspiratory pressure assistance and is supposed to be better than PSV for synchrony and tolerance, but reports are still controversial. Moreover, most of these studies are conducted in chronic obstructive pulmonary disease patients with respiratory failure; the results of these studies may not be applicable to surgical patients. Thus, we proposed to do compare these two modes in surgical Intensive Care Unit (ICU) patients as a randomized crossover study. Comparison of patient-ventilator asynchrony between PSV and PAV plus (PAV+) in surgical patients while weaning. After approval by the Hospital Ethics Committee, we enrolled twenty patients from surgical ICU of tertiary care institute. The patients were ventilated with pressure support mode (PSV) and PAV+ for 12 h as a crossover from one mode to another after 6 h while weaning. Average age and weight of patients were 41.80 ± 15.20 years (mean ± standard deviation [SD]) and 66.50 ± 12.47 (mean ± SD) kg, respectively. Comparing the asynchronies between the two modes, the mean number of total asynchronous recorded breaths in PSV was 7.05 ± 0.83 and 4.35 ± 5.62, respectively, during sleep and awake state, while the same were 6.75 ± 112.24 and 10.85 ± 11.33 in PAV+. Both PSV and PAV+ modes of ventilation performed similarly for patient-ventilator synchrony in surgical patients. In surgical patients with acute respiratory failure, dynamic inspiratory pressure assistance modalities are not superior to PSV with respect to cardiorespiratory

  7. Improving Stack Effect in Hot Humid Building Interiors with Hybrid Turbine Ventilator(s

    Directory of Open Access Journals (Sweden)

    Rifa Radia Tashkina

    2014-01-01

    Full Text Available Natural ventilation strategies have been applied through the ages to offer thermal comfort. At present, these techniques could be employed as one of the methods to overcome the electric consumption that comes from the burning of disproportionate fossil fuel to operate air conditioners. This air conditioning process is the main contributor of CO2 emissions. This paper focuses on the efficiency of stack ventilation which is one of the natural ventilation strategies, and at the same time attempts to overcome the problem of erratic wind flow and the low indoor/outdoor temperature difference in the hot, humid Malaysian climate. Wind flow and sufficient pressure difference are essential for stack ventilation, and as such the irregularity can be overcome with the use of the Hybrid Turbine Ventilator (HTV which extracts hot air from the interior of the building via the roof level. The extraction of hot air is constant and consistent throughout the day time as long as there is sunlight falling on the solar panel for solar electricity. The aim of this paper is to explore the different HTV strategies and find out which building dimensions is most expected to reduce maximum indoor air temperature of a given room in a real weather condition.

  8. [Consequences of mechanical ventilation on diaphragmatic function].

    Science.gov (United States)

    Jung, B; Gleeton, D; Daurat, A; Conseil, M; Mahul, M; Rao, G; Matecki, S; Lacampagne, A; Jaber, S

    2015-04-01

    Mechanical ventilation is associated with ventilator-induced diaphragmatic dysfunction (VIDD) in animal models and also in humans. The main pathophysiological pathways implicated in VIDD seems to be related to muscle inactivity but may also be the consequence of high tidal volumes. Systemic insults from side effects of medication, infection, malnutrition and hypoperfusion also play a part. The diaphragm is caught in the cross-fire of ventilation-induced and systemic-induced dysfunctions. Intracellular consequences of VIDD include oxidative stress, proteolysis, impaired protein synthesis, autophagy activation and excitation-contraction decoupling. VIDD can be diagnosed at the bedside using non-invasive magnetic stimulation of the phrenic nerves which is the gold standard. Other techniques involve patient's participation such as respiratory function tests or ultrasound examination. At this date, only spontaneous ventilatory cycles and perhaps phrenic nerve stimulation appear to diminish the severity of VIDD in humans but several pathways are currently being examined using animal models. Specific pharmacological options are currently under investigation in animal models. Copyright © 2014 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  9. Respiratory mechanics in mechanically ventilated patients.

    Science.gov (United States)

    Hess, Dean R

    2014-11-01

    Respiratory mechanics refers to the expression of lung function through measures of pressure and flow. From these measurements, a variety of derived indices can be determined, such as volume, compliance, resistance, and work of breathing. Plateau pressure is a measure of end-inspiratory distending pressure. It has become increasingly appreciated that end-inspiratory transpulmonary pressure (stress) might be a better indicator of the potential for lung injury than plateau pressure alone. This has resulted in a resurgence of interest in the use of esophageal manometry in mechanically ventilated patients. End-expiratory transpulmonary pressure might also be useful to guide the setting of PEEP to counterbalance the collapsing effects of the chest wall. The shape of the pressure-time curve might also be useful to guide the setting of PEEP (stress index). This has focused interest in the roles of stress and strain to assess the potential for lung injury during mechanical ventilation. This paper covers both basic and advanced respiratory mechanics during mechanical ventilation. Copyright © 2014 by Daedalus Enterprises.

  10. High tidal volume ventilation in infant mice.

    Science.gov (United States)

    Cannizzaro, Vincenzo; Zosky, Graeme R; Hantos, Zoltán; Turner, Debra J; Sly, Peter D

    2008-06-30

    Infant mice were ventilated with either high tidal volume (V(T)) with zero end-expiratory pressure (HVZ), high V(T) with positive end-expiratory pressure (PEEP) (HVP), or low V(T) with PEEP. Thoracic gas volume (TGV) was determined plethysmographically and low-frequency forced oscillations were used to measure the input impedance of the respiratory system. Inflammatory cells, total protein, and cytokines in bronchoalveolar lavage fluid (BALF) and interleukin-6 (IL-6) in serum were measured as markers of pulmonary and systemic inflammatory response, respectively. Coefficients of tissue damping and tissue elastance increased in all ventilated mice, with the largest rise seen in the HVZ group where TGV rapidly decreased. BALF protein levels increased in the HVP group, whereas serum IL-6 rose in the HVZ group. PEEP keeps the lungs open, but provides high volumes to the entire lungs and induces lung injury. Compared to studies in adult and non-neonatal rodents, infant mice demonstrate a different response to similar ventilation strategies underscoring the need for age-specific animal models.

  11. Collective fluid mechanics of honeybee nest ventilation

    Science.gov (United States)

    Gravish, Nick; Combes, Stacey; Wood, Robert J.; Peters, Jacob

    2014-11-01

    Honeybees thermoregulate their brood in the warm summer months by collectively fanning their wings and creating air flow through the nest. During nest ventilation workers flap their wings in close proximity in which wings continuously operate in unsteady oncoming flows (i.e. the wake of neighboring worker bees) and near the ground. The fluid mechanics of this collective aerodynamic phenomena are unstudied and may play an important role in the physiology of colony life. We have performed field and laboratory observations of the nest ventilation wing kinematics and air flow generated by individuals and groups of honeybee workers. Inspired from these field observations we describe here a robotic model system to study collective flapping wing aerodynamics. We microfabricate arrays of 1.4 cm long flapping wings and observe the air flow generated by arrays of two or more fanning robotic wings. We vary phase, frequency, and separation distance among wings and find that net output flow is enhanced when wings operate at the appropriate phase-distance relationship to catch shed vortices from neighboring wings. These results suggest that by varying position within the fanning array honeybee workers may benefit from collective aerodynamic interactions during nest ventilation.

  12. Higher Fresh Gas Flow Rates Decrease Tidal Volume During Pressure Control Ventilation.

    Science.gov (United States)

    Mohammad, Shazia; Gravenstein, Nikolaus; Gonsalves, Drew; Vasilopoulos, Terrie; Lampotang, Samsun

    2017-05-01

    We observed that increasing fresh gas flow (FGF) decreased exhaled tidal volume (VT) during pressure control ventilation (PCV). A literature search produced no such description whereby unintended VT changes occur with FGF changes during PCV. To model an infant's lungs, 1 lung of a mechanical lung model (Dual Adult TTL 1600; Michigan Instruments, Inc, Grand Rapids, MI) was set at a compliance of 0.0068 L/cm H2O. An Rp50 resistor (27.2 cm H2O/L/s at 15 L/min) simulated normal bronchial resistance. The simulated lung was connected to a pediatric breathing circuit via a 3.5-mm cuffed endotracheal tube. A ventilator with PCV capability (Model 7900; Aestiva, GE Healthcare, Madison, WI) measured exhaled VT, and a flow monitor (NICO; Respironics, Murraysville, PA) measured peak inspiratory flow, positive end-expiratory pressure (PEEP), and peak inspiratory pressure. In PCV mode, exhaled VT displayed by the ventilator at FGF rates of 1, 6, 10, and 15 L/min was manually recorded across multiple ventilator settings. This protocol was repeated for the Avance CS2 anesthesia machine (GE Healthcare). For the Aestiva, higher FGF rates in PCV mode decreased exhaled VT. Exhaled VT for FGFs of 1, 6, 10, and 15 L/min were on average 48, 34.9, 16.5, and 10 mL, respectively, at ventilator settings of inspiratory pressure of 10 cm H2O, PEEP of 0 cm H2O, and respiratory rate of 20 breaths/min. This is a decrease by up to 27%, 65.6%, and 79.2% when FGFs of 6, 10, and 15 L/min are compared with a FGF of 1 L/min, respectively. In the GE Avance CS2 at the same ventilator settings, VT for FGF rates of 1, 6, 10, and 15 L/min were on average 46, 43, 40.4, and 39.7 mL, respectively. The FGF effect on VT was not as pronounced with the GE Avance CS2 as with the GE Aestiva. FGF has a significant effect on VT during PCV in the Aestiva bellows ventilator, suggesting caution when changing FGF during PCV in infants. Our hypothesis is that at higher FGF rates, an inadvertent PEEP is developed by the flow

  13. Advanced Controls for Residential Whole-House Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Turner, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    Whole-house ventilation systems are becoming commonplace in new construction, remodeling/renovation, and weatherization projects, driven by combinations of specific requirements for indoor air quality (IAQ), health and compliance with standards, such as ASHRAE 62.2. Ventilation systems incur an energy penalty on the home via fan power used to drive the airflow, and the additional space-conditioning load associated with heating or cooling the ventilation air. Finding a balance between IAQ and energy use is important if homes are to be adequately ventilated while not increasing the energy burden. This study used computer simulations to examine RIVEC the Residential Integrated Ventilation Controller - a prototype ventilation controller that aims to deliver whole-house ventilation rates that comply with ventilation standards, for the minimum use of energy. Four different whole-house ventilation systems were simulated, both with and without RIVEC, so that the energy and IAQ results could be compared. Simulations were conducted for 13 US climate zones, three house designs, and three envelope leakage values. The results showed that the RIVEC controller could typically return ventilation energy savings greater than 40percent without compromising long-term chronic or short-term acute exposures to relevant indoor contaminants. Critical and average peak power loads were also reduced as a consequence of using RIVEC.

  14. Why we ventilate our houses - An historical look

    Energy Technology Data Exchange (ETDEWEB)

    Matson, Nance E.; Sherman, Max H.

    2004-05-14

    The knowledge of how to ventilate buildings, and how much ventilation is necessary for human health and comfort, has evolved over centuries of trial and error. Humans and animals have developed successful solutions to the problems of regulating temperature and removing air pollutants through the use of ventilation. These solutions include ingenious construction methods, such as engineered passive ventilation (termite mounds and passive stacks), mechanical means (wing-powered, fans), and an evolving effort to identify problems and develop solutions. Ventilation can do more than help prevent building occupants from getting sick; it can provide an improved indoor environment. Codes and standards provide minimum legal requirements for ventilation, but the need for ventilation goes beyond code minima. In this paper we will look at indoor air pollutant sources over time, the evolution of ventilation strategies, current residential ventilation codes and standards (e.g., recently approved ASHRAE Standard 62.2), and briefly discuss ways in which we can go beyond the standards to optimize residential ventilation, reduce indoor air quality problems, and provide corresponding social and economic benefit.

  15. [Independent lung ventilation during general anaesthesia--preliminary report].

    Science.gov (United States)

    Sawulski, Sławomir; Nestorowicz, Andrzej; Sawicki, Marek; Kowalczyk, Michał; Stoń, Mirosław

    2010-01-01

    Unitaleral lung pathology presents a serious challenge for the anaesthesiologist. Conventional ventilation usually leads to over distension of the non-affected lung and hypoventilation of the affected lung. The optimal ventilatory strategy in such situations, is intubation with a double lumen tube and independent lung ventilation with two respirators. This is expensive and difficult, especially in an operating room. A novel approach to this problem is based on the use of a single ventilator with a volume splitter, which enables the independent ventilation of each lung, with the same frequency but different volumes, I:E ratios and PEEPs. We used the splitter in thirty-four patients, of both sexes, aged 19-78 years, and scheduled for elective thoracic surgery. All patients were intubated with a double lumen tube and ventilated in the supine and lateral positions with and without the splitter. When the lateral position was used, the volume delivered by the ventilator was split equally to each lung. In the lateral position, without the splitter, the distribution of gas delivered by the ventilator was unequal: the dependent lung receiving 47.4 +/- 6.8% of the total volume, and the non-dependent lung receiving 52.6 +/- 6.8%. When the splitter was used, both lungs were ventilated with equal volumes. All patients were cardiovasculary stable. A novel method of ventilation during anaesthesia is described, opening up new possibilities for thoracic anaesthesia that allows easy and atraumatic independent lung ventilation.

  16. Pulmonary ventilation defects in older never-smokers.

    Science.gov (United States)

    Sheikh, Khadija; Paulin, Gregory A; Svenningsen, Sarah; Kirby, Miranda; Paterson, Nigel A M; McCormack, David G; Parraga, Grace

    2014-08-01

    Hyperpolarized (3)He MRI previously revealed spatially persistent ventilation defects in healthy, older compared with healthy, younger never-smokers. To understand better the physiological consequences and potential relevance of (3)He MRI ventilation defects, we evaluated (3)He-MRI ventilation-defect percent (VDP) and the effect of deep inspiration (DI) and salbutamol on VDP in older never-smokers. To identify the potential determinants of ventilation defects in these subjects, we evaluated dyspnea, pulmonary function, and cardiopulmonary exercise test (CPET) measurements, as well as occupational and second-hand smoke exposure. Fifty-two never-smokers (71 ± 6 yr) with no history of chronic respiratory disease were evaluated. During a single visit, pulmonary function tests, CPET, and (3)He MRI were performed and the Burden of Obstructive Lung Disease questionnaire administered. For eight of 52 subjects, there was spirometry evidence of airflow limitation (Global Initiative for Chronic Obstructive Lung Disease-Unclassified, I, and II), and occupational exposure was reported in 13 of 52 subjects. In 13 of 52 (25%) subjects, there were no ventilation defects and in 39 of 52 (75%) subjects, ventilation defects were observed. For those subjects with ventilation defects, six of 39 showed a VDP response to DI/salbutamol. Ventilation heterogeneity and VDP were significantly greater, and forced expiratory volume in 1 s (FEV1)/forced vital capacity was significantly lower (P ventilation defects with a response to DI/salbutamol than subjects with ventilation defects without a response to DI/salbutamol and subjects without ventilation defects. In a step-wise, forward multivariate model, FEV1, inspiratory capacity, and airway resistance significantly predicted VDP (R(2) = 0.45, P ventilation defects not reversed by DI/salbutamol; such ventilation defects were likely related to irreversible airway narrowing/collapse but not to dyspnea and decreased exercise capacity. Copyright

  17. Relationship between clothing ventilation and thermal insulation.

    Science.gov (United States)

    Bouskill, L M; Havenith, G; Kuklane, K; Parsons, K C; Withey, W R

    2002-01-01

    Air layers trapped within a clothing microenvironment contribute to the thermal insulation afforded by the ensemble. Any exchange of air between the external environment and these trapped air layers results in a change in the ensemble's thermal insulation and water vapor resistance characteristics. These effects are seldom taken into account when considering the effects of clothing on human heat balance, the thermal characteristics usually being restricted to intrinsic insulation and intrinsic evaporative resistance measurements on static manikins. Environmental assessments based on these measurements alone may therefore lead to under-(or over-) estimation of thermal stress of the worker. The aim of this study was to quantify the relationship between clothing ventilation and thermal insulation properties. A one-layer, air-impermeable ensemble and a three-layer, air-permeable ensemble were tested using an articulated, thermal manikin in a controlled climate chamber (ta = tr = 10 degrees C, PaH2O = 0.73 kPa). The manikin, which was designed for thermal insulation measurements, was also equipped with a system to determine clothing ventilation. Baseline measurements of clothing ventilation (VT) and thermal insulation (total clothing insulation: I(T)--measured, intrinsic insulation: Icl--calculated) were made of the clothing with the manikin standing stationary in still air conditions. Increased clothing ventilation was induced when the manikin "walked" (walking speeds of 0.37 m/sec and 0.77 m/sec) and by increasing the environmental air speed (Va = 1.0 m/sec). These increases in VT reduced Icl, this being ascribed to the increased heat transfer from the manikin skin surface to the cooler external environment due to the exchange of air between the clothing microenvironment and the external environment. Measured air exchanges were shown to have a potential heat exchange capacity of up to 17 and 161 W/m2 for the one- and three-layer ensembles, respectively, emphasizing

  18. The influence of music during mechanical ventilation and weaning from mechanical ventilation: A review.

    Science.gov (United States)

    Hetland, Breanna; Lindquist, Ruth; Chlan, Linda L

    2015-01-01

    Mechanical ventilation (MV) causes many distressing symptoms. Weaning, the gradual decrease in ventilator assistance leading to termination of MV, increases respiratory effort, which may exacerbate symptoms and prolong MV. Music, a non-pharmacological intervention without side effects may benefit patients during weaning from mechanical ventilatory support. A narrative review of OVID Medline, PsychINFO, and CINAHL databases was conducted to examine the evidence for the use of music intervention in MV and MV weaning. Music intervention had a positive impact on ventilated patients; 16 quantitative and 2 qualitative studies were identified. Quantitative studies included randomized clinical trials (10), case controls (3), pilot studies (2) and a feasibility study. Evidence supports music as an effective intervention that can lesson symptoms related to MV and promote effective weaning. It has potential to reduce costs and increase patient satisfaction. However, more studies are needed to establish its use during MV weaning. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Personal exposure between people in a room ventilated by textile terminals - with and without personalized ventilation

    DEFF Research Database (Denmark)

    Nielsen, P. V.; Hyldgaard, C.E.; Melikov, Arsen Krikor

    2005-01-01

    The investigation is made in a room ventilated by an air distribution system based on a textile terminal. The air distribution in the room is mainly controlled by buoyancy forces from the heat sources, although the flow from the textile terminal can be characterized as a passive displacement flow...... with a downward direction in areas without thermal load. The system is extended by a personalized ventilation system to study the improved protection of people in a room. The investigation involves full-scale experiments with two breathing thermal manikins. One manikin is the source and the other the target....... In general it is found that when the air is supplied from the textile terminal alone, the flow in the room is fully mixed with a limited protection of the occupants. It is shown that the personalized ventilation improves the protection of occupants by increasing the personal exposure index....

  20. Effects of Multiple Ventilation Courses and Duration of Mechanical Ventilation on Respiratory Outcomes in Extremely Low-Birth-Weight Infants.

    Science.gov (United States)

    Jensen, Erik A; DeMauro, Sara B; Kornhauser, Michael; Aghai, Zubair H; Greenspan, Jay S; Dysart, Kevin C

    2015-11-01

    Extubation failure is common in extremely preterm infants. The current paucity of data on the adverse long-term respiratory outcomes associated with reinitiation of mechanical ventilation prevents assessment of the risks and benefits of a trial of extubation in this population. To evaluate whether exposure to multiple courses of mechanical ventilation increases the risk of adverse respiratory outcomes before and after adjustment for the cumulative duration of mechanical ventilation. We performed a retrospective cohort study of extremely low-birth-weight (ELBW; birth weight mechanical ventilation. Analysis was conducted between November 2014 and February 2015. Data were obtained from the Alere Neonatal Database. The primary study exposures were the cumulative duration of mechanical ventilation and the number of ventilation courses. The primary outcome was bronchopulmonary dysplasia (BPD) among survivors. Secondary outcomes were death, use of supplemental oxygen at discharge, and tracheostomy. We identified 3343 ELBW infants, of whom 2867 (85.8%) survived to discharge. Among the survivors, 1695 (59.1%) were diagnosed as having BPD, 856 (29.9%) received supplemental oxygen at discharge, and 31 (1.1%) underwent tracheostomy. Exposure to a greater number of mechanical ventilation courses was associated with a progressive increase in the risk of BPD and use of supplemental oxygen at discharge. Compared with a single ventilation course, the adjusted odds ratios for BPD ranged from 1.88 (95% CI, 1.54-2.31) among infants with 2 ventilation courses to 3.81 (95% CI, 2.88-5.04) among those with 4 or more courses. After adjustment for the cumulative duration of mechanical ventilation, the odds of BPD were only increased among infants exposed to 4 or more ventilation courses (adjusted odds ratio, 1.44; 95% CI, 1.04-2.01). The number of ventilation courses was not associated with increased risk of supplemental oxygen use at discharge after adjustment for the length of ventilation

  1. Neurally adjusted ventilatory assist and proportional assist ventilation both improve patient-ventilator interaction.

    Science.gov (United States)

    Schmidt, Matthieu; Kindler, Felix; Cecchini, Jérôme; Poitou, Tymothée; Morawiec, Elise; Persichini, Romain; Similowski, Thomas; Demoule, Alexandre

    2015-02-25

    The objective was to compare the impact of three assistance levels of different modes of mechanical ventilation; neurally adjusted ventilatory assist (NAVA), proportional assist ventilation (PAV), and pressure support ventilation (PSV) on major features of patient-ventilator interaction. PSV, NAVA, and PAV were set to obtain a tidal volume (VT) of 6 to 8 ml/kg (PSV₁₀₀, NAVA₁₀₀, and PAV₁₀₀) in 16 intubated patients. Assistance was further decreased by 50% (PSV₅₀, NAVA₅₀, and PAV₅₀) and then increased by 50% (PSV₁₅₀, NAVA₁₅₀, and PAV₁₅₀) with all modes. The three modes were randomly applied. Airway flow and pressure, electrical activity of the diaphragm (EAdi), and blood gases were measured. VT, peak EAdi, coefficient of variation of VT and EAdi, and the prevalence of the main patient-ventilator asynchronies were calculated. PAV and NAVA prevented the increase of VT with high levels of assistance (median 7.4 (interquartile range (IQR) 5.7 to 10.1) ml/kg and 7.4 (IQR, 5.9 to 10.5) ml/kg with PAV₁₅₀ and NAVA₁₅₀ versus 10.9 (IQR, 8.9 to 12.0) ml/kg with PSV₁₅₀, P variation of VT was higher with NAVA and PAV (19 (IQR, 14 to 31)% and 21 (IQR 16 to 29)% with NAVA₁₀₀ and PAV₁₀₀ versus 13 (IQR 11 to 18)% with PSV₁₀₀, P ventilator asynchrony in fairly similar ways compared with PSV. Further studies are needed to evaluate the possible clinical benefits of NAVA and PAV on clinical outcomes. Clinicaltrials.gov NCT02056093 . Registered 18 December 2013.

  2. Which Nebulizer Position Should Be Avoided? An Extended Study of Aerosol Delivery and Ventilator Performance during Noninvasive Positive Pressure Ventilation.

    Science.gov (United States)

    Peng, Yun; Dai, Bing; Hu, Chun-Xiang; Su, Jia; Tan, Wei; Zhao, Hong-Wen; Kang, Jian

    2017-12-06

    Research on the effect of nebulizer location on aerosol delivery during noninvasive ventilation has reached inconsistent conclusions. To investigate the effects of nebulizer position on aerosol delivery efficiency and ventilator performance during noninvasive ventilation. The Active Servo Lung 5000 respiratory simulation system (ASL5000) was used to simulate a COPD patient. The noninvasive ventilator was set to the spontaneous breathing mode. Six nebulizer positions, 2 exhalation valve types (single-arch exhalation port and whisper swivel), 4 combinations of inspiratory and expiratory pressure, and 2 respiratory rates were used. Significant differences between nebulizer positions existed in aerosol delivery (p ventilator outlet. When the nebulizer was located between the exhalation valve and the simulated lung, increased inspiratory pressure increased and increased expiratory pressure decreased delivery efficiency (both p ventilator, no obvious trend was observed. Compared to baseline, nebulization lowered the air leakage volume displayed on the ventilator. There were no differences in ventilator performance between different nebulizer positions. The closer the nebulizer was to the exhalation valves or ventilator, the lower the aerosol delivery efficiency. Nebulizer position had little clinically significant effect on ventilator performance. © 2017 S. Karger AG, Basel.

  3. Instrumentation a reader

    CERN Document Server

    Pope, P

    1990-01-01

    This book contains a selection of papers and articles in instrumentation previously pub­ lished in technical periodicals and journals of learned societies. Our selection has been made to illustrate aspects of current practice and applications of instrumentation. The book does not attempt to be encyclopaedic in its coverage of the subject, but to provide some examples of general transduction techniques, of the sensing of particular measurands, of components of instrumentation systems and of instrumentation practice in two very different environments, the food industry and the nuclear power industry. We have made the selection particularly to provide papers appropriate to the study of the Open University course T292 Instrumentation. The papers have been chosen so that the book covers a wide spectrum of instrumentation techniques. Because of this, the book should be of value not only to students of instrumen­ tation, but also to practising engineers and scientists wishing to glean ideas from areas of instrumen...

  4. Sedation and memories of patients subjected to mechanical ventilation in an intensive care unit.

    Science.gov (United States)

    Costa, Jaquilene Barreto da; Marcon, Sonia Silva; Macedo, Claudia Rejane Lima de; Jorge, Amaury Cesar; Duarte, Péricles Almeida Delfino

    2014-01-01

    To investigate the relationship between sedation and the memories reported by patients subjected to mechanical ventilation following discharge from the intensive care unit. This prospective, observational, cohort study was conducted with individuals subjected to mechanical ventilation who remained in the intensive care unit for more than 24 hours. Clinical statistics and sedation records were extracted from the participants' clinical records; the data relative to the participants' memories were collected using a specific validated instrument. Assessment was performed three months after discharge from the intensive care unit. A total of 128 individuals were assessed, most of whom (84.4%) reported recollections from their stay in the intensive care unit as predominantly a combination of real and illusory events. The participants subjected to sedation (67.2%) at deep levels (Richmond Agitation-Sedation Scale [RASS] -4 and -5) for more than two days and those with psychomotor agitation (33.6%) exhibited greater susceptibility to occurrence of illusory memories (p>0.001). The probability of the occurrence of illusory memories was greater among the participants who were subjected to deep sedation. Sedation seems to be an additional factor that contributed to the occurrence of illusory memories in severely ill individuals subjected to mechanical ventilation.

  5. Computational fluid dynamics in ventilation. 4: Commercial application of CFD in ventilation

    Science.gov (United States)

    Nielsen, Peter V.

    In considering the commercial applications of Computational Fluid Dynamics (CFD) in ventilation, the following are addressed: typical markets (airport centers, large theaters, atria, shopping malls, etc.); typical problems to be solved (energy flow, draft, ventilation effectiveness, pressure distribution, etc.); and high priority areas, activities and quantities (fast preprocessing, effective visualization software, etc.). It is stated that the commercial application of CFD may be looked upon as an advanced 'zonal' model. The 'zonal' model concept is outlined and CFD with large control volumes is considered. An illustrated example of air flow simulation in a theater is given.

  6. Air quality Performance of Ductless Personalized Ventilation in Conjunction with Displacement Ventilation: Impact of Walking Person

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Lu, Pengfei; Melikov, Arsen Krikor

    2015-01-01

    The present experiment evaluates the impact of air disturbances from a walking person on inhaled air by ductless personalized ventilation (DPV) with displacement ventilation (DV), when a seated occupant is the source of pollution: bio-effluents and exhaled air. The measurements took place in a full......-scale office room with two side by side workstations. Each desk included a DPV, a personal computer and desk lamps. Two dressed, breathing thermal manikins were used as seated occupants. DV floorstanding air supply was installed at the wall facing the workstations. A real person was walking between the desks...

  7. Magnetic Resonance Imaging of Ventilation and Perfusion in the Lung

    Science.gov (United States)

    Prisk, Gordon Kim (Inventor); Hopkins, Susan Roberta (Inventor); Buxton, Richard Bruce (Inventor); Pereira De Sa, Rui Carlos (Inventor); Theilmann, Rebecca Jean (Inventor); Cronin, Matthew Vincent (Inventor)

    2017-01-01

    Methods, devices, and systems are disclosed for implementing a fully quantitative non-injectable contrast proton MRI technique to measure spatial ventilation-perfusion (VA/Q) matching and spatial distribution of ventilation and perfusion. In one aspect, a method using MRI to characterize ventilation and perfusion in a lung includes acquiring an MR image of the lung having MR data in a voxel and obtaining a breathing frequency parameter, determining a water density value, a specific ventilation value, and a perfusion value in at least one voxel of the MR image based on the MR data and using the water density value to determine an air content value, and determining a ventilation-perfusion ratio value that is the product of the specific ventilation value, the air content value, the inverse of the perfusion value, and the breathing frequency.

  8. Technology for noninvasive mechanical ventilation: looking into the black box

    Directory of Open Access Journals (Sweden)

    Ramon Farré

    2016-03-01

    Full Text Available Current devices for providing noninvasive respiratory support contain sensors and built-in intelligence for automatically modifying ventilation according to the patient's needs. These devices, including automatic continuous positive airway pressure devices and noninvasive ventilators, are technologically complex and offer a considerable number of different modes of ventilation and setting options, the details of which are sometimes difficult to capture by the user. Therefore, better predicting and interpreting the actual performance of these ventilation devices in clinical application requires understanding their functioning principles and assessing their performance under well controlled bench test conditions with simulated patients. This concise review presents an updated perspective of the theoretical basis of intelligent continuous positive airway pressure and noninvasive ventilation devices, and of the tools available for assessing how these devices respond under specific ventilation phenotypes in patients requiring breathing support.

  9. Control strategies for demand controlled ventilation in dwellings

    DEFF Research Database (Denmark)

    Nielsen, Toke Rammer; Drivsholm, Christian

    2011-01-01

    Ventilation of Danish and many other European dwellings has in the past mainly been achieved by natural ventilation or mechanical exhaust systems. Requirements for energy efficiency is changing this picture and mechanical ventilation with balanced exhaust and supply, efficient heat recovery...... high. Too low ventilation rate results in poor air quality for the occupants and moisture risk. Too high ventilation rate results in unnecessary energy consumption. This paper presents results from a study where demand controlled ventilation was installed in an existing single family house....... In the studied house two control strategies were tested. A simple strategy where all sensors and controls were located in the air handling unit and only the speed of the fans can be controlled, and a complex strategy where sensors were placed in each room and where individual control of air flow in each room...

  10. Networked Instrumentation Element

    Data.gov (United States)

    National Aeronautics and Space Administration — Armstrong researchers have developed a networked instrumentation system that connects modern experimental payloads to existing analog and digital communications...

  11. Ocean Optics Instrumentation Systems

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides instrumentation suites for a wide variety of measurements to characterize the ocean’s optical environment. These packages have been developed to...

  12. Perceived decisional responsibility for mechanical ventilation and weaning

    DEFF Research Database (Denmark)

    Haugdahl, Hege S; Storli, Sissel; Rose, Louise

    2014-01-01

    AIM: To explore variability in perceptions of nurse managers and physician directors regarding roles, responsibilities and clinical-decision making related to mechanical ventilator weaning in Norwegian intensive care units (ICUs). BACKGROUND: Effective teamwork is crucial for providing optimal...... patient care in ICU. More knowledge on nurses' and physicians' perceptions of responsibility in clinical decision-making for mechanical ventilation is needed. METHODS: Self-administered survey of mechanical ventilation and weaning responsibilities was sent to nurse managers and physician directors...

  13. Chest trauma: A case for single lung ventilation

    OpenAIRE

    Nagaraj Pandharikar; Anil Sachdev; Neeraj Gupta; Suresh Gupta; Dhiren Gupta

    2016-01-01

    Chest trauma is one of the important causes of mortality and morbidity in pediatric trauma patients. The complexity, magnitude, and type of lung injury make it extremely challenging to provide optimal oxygenation and ventilation while protecting the lung from further injury due to mechanical ventilation. Independent lung ventilation is used sporadically in these patients who do not respond to these conventional ventilatory strategies using double-lumen endotracheal tubes, bronchial blocker ba...

  14. Recommended Ventilation Strategies for Energy-Efficient Production Homes

    Energy Technology Data Exchange (ETDEWEB)

    Roberson, J.; Brown, R.; Koomey, J.; Warner, J.; Greenberg, S.

    1998-12-01

    This report evaluates residential ventilation systems for the U.S. Environmental Protection Agency's (EPA's) ENERGY STAR{reg_sign} Homes program and recommends mechanical ventilation strategies for new, low-infiltration, energy-efficient, single-family, ENERGY STAR production (site-built tract) homes in four climates: cold, mixed (cold and hot), hot humid, and hot arid. Our group in the Energy Analysis Department at Lawrence Berkeley National Lab compared residential ventilation strategies in four climates according to three criteria: total annualized costs (the sum of annualized capital cost and annual operating cost), predominant indoor pressure induced by the ventilation system, and distribution of ventilation air within the home. The mechanical ventilation systems modeled deliver 0.35 air changes per hour continuously, regardless of actual infiltration or occupant window-opening behavior. Based on the assumptions and analysis described in this report, we recommend independently ducted multi-port supply ventilation in all climates except cold because this strategy provides the safety and health benefits of positive indoor pressure as well as the ability to dehumidify and filter ventilation air. In cold climates, we recommend that multi-port supply ventilation be balanced by a single-port exhaust ventilation fan, and that builders offer balanced heat-recovery ventilation to buyers as an optional upgrade. For builders who continue to install forced-air integrated supply ventilation, we recommend ensuring ducts are airtight or in conditioned space, installing a control that automatically operates the forced-air fan 15-20 minutes during each hour that the fan does not operate for heating or cooling, and offering ICM forced-air fans to home buyers as an upgrade.

  15. Forced oscillation assessment of respiratory mechanics in ventilated patients

    OpenAIRE

    Navajas, Daniel; Farré, Ramon

    2000-01-01

    The forced oscillation technique (FOT) is a method for non-invasively assessing respiratory mechanics that is applicable both in paralysed and non-paralysed patients. As the FOT requires a minimal modification of the conventional ventilation setting and does not interfere with the ventilation protocol, the technique is potentially useful to monitor patient mechanics during invasive and noninvasive ventilation. FOT allows the assessment of the respiratory system linearity by measuring resistan...

  16. [Monitorization of respiratory mechanics in the ventilated patient].

    Science.gov (United States)

    García-Prieto, E; Amado-Rodríguez, L; Albaiceta, G M

    2014-01-01

    Monitoring during mechanical ventilation allows the measurement of different parameters of respiratory mechanics. Accurate interpretation of these data can be useful for characterizing the situation of the different components of the respiratory system, and for guiding ventilator settings. In this review, we describe the basic concepts of respiratory mechanics, their interpretation, and their potential use in fine-tuning mechanical ventilation. Copyright © 2013 Elsevier España, S.L. y SEMICYUC. All rights reserved.

  17. Airway Humidification During High-Frequency Percussive Ventilation

    Science.gov (United States)

    2009-03-01

    Association for Respi- ratory Care (AARC) recommendations for the minimum acceptable heating and humidification during mechanical ventilation ( 30°C...Care. AARC clinical practice guideline: humidification during mechanical ventilation . Respir Care 1992;37(8):887-890. 3. Branson RD. The effects of...Airway Humidification During High-Frequency Percussive Ventilation Patrick F Allan MD, Michael J Hollingsworth CRT, Gordon C Maniere CRT, Anthony K

  18. Single-shell tank ventilation upgrades needs analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Kriskovich, J.R., Fluor Daniel Hanford

    1997-02-03

    This report was written to comply with the objectives of the Hanford Federal Facility Agreement and Consent Order, Tri-Party Agreement Milestone M-43-03 Provide to the Washington State Department of Ecology and Department of Health the Results of the Single-Shell Tank Ventilation Upgrades Needs Analysis. The needs analysis consists of identifying the current type and status of each single-shell tank ventilation system, identifying current and projected authorization basis requirements, and identifying ventilation system compliance deficiencies.

  19. Study of Fallout Shelter Ventilation Kit Placement Design

    Science.gov (United States)

    1980-05-01

    shelter spaces display a great deal of Regional variation , caused mostly by differences in zonal ventilation requirements. These large Regional...Ma -M FEMA Work Unit 12170 Contmct No. DCPA01-76-C-0318 L EF 0 FINAL REPORT RTI/1703/00-OSF STUDY OF FALLOUT SHELTER VENTILATION KIT PLACEMENT 0...Fallout Shelter Ventilation Kit Placement Design by S. •. York, III and J. A. Armstrong for Vt FEDERAL EMERGENCY MANAGEMENfT AGENCY Washington, D.C. 2041

  20. Investigations of the Sound Generated by Supercavity Ventilation

    Science.gov (United States)

    2009-08-20

    cavity- ventilating gas jets, and the outcome of this project will be an understanding of this mechanism and its probable impact on the self-noise problem...geometry and physical mechanisms governing the jet-cavity interaction. The simplest approxima- tion involves a ventilated supercavity in the form of a...interfere with successful vehicle deployment A principal mechanisms of noise generation is believed to be the impingement of ventilating gas jets on the

  1. Computer Simulation of Buildings Cooled by Natural Ventilation.

    Science.gov (United States)

    1983-05-01

    performance of a building, the influence of natural infiltration on mechanical ventilation systems, and the study of smoke in the event of a fire...natural infiltration on mechanical ventilation systems, and the study of smoke in the event of a fire. Unclassified SECURITY CLASSIrIcATION OF TIIS PAGE...whether open or closed). Other influences include the operation of mechanical ventilation systems and the transient effects caused by opening and

  2. Influence of Anticholinesterase on Distribution of Ventilation and Gas Exchange

    Science.gov (United States)

    1990-10-01

    the observed pressure profile measured at the catheter tip. Following catheter placement, mechanical ventilation with a tidal volume of 15 ml/kg was...OTEC FILE COPY USAFSAM-TR-90-30 AD-A229 341 INFLUENCE OF ANTICHOLINESTERASE ON DISTRIBUTION OF VENTILATION AND GAS EXCHANGE Harold I. Modell, Ph.D...Distribution of Ventilation and Gas Exchange 12. PERSONAL AUTHOR(S) Modell, Harold I. 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year

  3. Mechanical Ventilation-induced Diaphragm Atrophy Strongly Impacts Clinical Outcomes.

    Science.gov (United States)

    Goligher, Ewan C; Dres, Martin; Fan, Eddy; Rubenfeld, Gordon D; Scales, Damon C; Herridge, Margaret S; Vorona, Stefannie; Sklar, Michael C; Rittayamai, Nuttapol; Lanys, Ashley; Murray, Alistair; Brace, Deborah; Urrea, Cristian; Reid, W Darlene; Tomlinson, George; Slutsky, Arthur S; Kavanagh, Brian P; Brochard, Laurent J; Ferguson, Niall D

    2017-09-20

    Rationale Diaphragm dysfunction worsens outcomes in mechanically ventilated patients but the clinical impact of potentially preventable changes in diaphragm structure and function due to mechanical ventilation is unknown. Objectives To determine whether diaphragm atrophy developing during mechanical ventilation leads to prolonged ventilation. Methods Diaphragm thickness was measured daily by ultrasound in adults requiring invasive mechanical ventilation; inspiratory effort was assessed by thickening fraction. The primary outcome was time to liberation from ventilation. Secondary outcomes included complications (reintubation, tracheostomy, prolonged ventilation, or death). Associations were adjusted for age, severity of illness, sepsis, sedation, neuromuscular blockade, and comorbidity. Measurements and Main Results Of 211 patients enrolled, 191 had two or more diaphragm thickness measurements. Thickness decreased more than 10% in 78 patients (41%) by median day 4 (IQR 3-5). Development of decreased thickness was associated with a lower daily probability of liberation from ventilation (adjusted HR 0.69, 95%CI 0.54-0.87, per 10% decrease), prolonged ICU admission (duration ratio 1.71, 95%CI 1.29-2.27), and a higher risk of complications (OR 3.00, 95%CI 1.34-6.72). Development of increased thickness (n=47, 24%) also predicted prolonged ventilation (duration ratio 1.38, 95%CI 1.00-1.90). Decreasing thickness was related to abnormally low inspiratory effort; increasing thickness was related to excessive effort. Patients with thickening fraction between 15-30% (similar to breathing at rest) during the first 3 days had the shortest duration of ventilation. Conclusions Diaphragm atrophy developing during mechanical ventilation strongly impacts clinical outcomes. Targeting an inspiratory effort level similar to that of healthy subjects at rest might accelerate liberation from ventilation.

  4. 46 CFR 177.600 - Ventilation of enclosed and partially enclosed spaces.

    Science.gov (United States)

    2010-10-01

    ... ventilation system unless natural ventilation in all ordinary weather conditions is satisfactory to the OCMI... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation of enclosed and partially enclosed spaces... PASSENGER VESSELS (UNDER 100 GROSS TONS) CONSTRUCTION AND ARRANGEMENT Ventilation § 177.600 Ventilation of...

  5. Neonatal and adult ICU ventilators to provide ventilation in neonates, infants, and children: a bench model study.

    Science.gov (United States)

    Vignaux, Laurence; Piquilloud, Lise; Tourneux, Pierre; Jolliet, Philippe; Rimensberger, Peter C

    2014-10-01

    Using a bench test model, we investigated the hypothesis that neonatal and/or adult ventilators equipped with neonatal/pediatric modes currently do not reliably administer pressure support (PS) in neonatal or pediatric patient groups in either the absence or presence of air leaks. PS was evaluated in 4 neonatal and 6 adult ventilators using a bench model to evaluate triggering, pressurization, and cycling in both the absence and presence of leaks. Delivered tidal volumes were also assessed. Three patients were simulated: a preterm infant (resistance 100 cm H2O/L/s, compliance 2 mL/cm H2O, inspiratory time of the patient [TI] 400 ms, inspiratory effort 1 and 2 cm H2O), a full-term infant (resistance 50 cm H2O/L/s, compliance 5 mL/cm H2O, TI 500 ms, inspiratory effort 2 and 4 cm H2O), and a child (resistance 30 cm H2O/L/s, compliance 10 mL/cm H2O, TI 600 ms, inspiratory effort 5 and 10 cm H2O). Two PS levels were tested (10 and 15 cm H2O) with and without leaks and with and without the leak compensation algorithm activated. Without leaks, only 2 neonatal ventilators and one adult ventilator had trigger delays under a given predefined acceptable limit (1/8 TI). Pressurization showed high variability between ventilators. Most ventilators showed TI in excess high enough to seriously impair patient-ventilator synchronization (> 50% of the TI of the subject). In some ventilators, leaks led to autotriggering and impairment of ventilation performance, but the influence of leaks was generally lower in neonatal ventilators. When a noninvasive ventilation algorithm was available, this was partially corrected. In general, tidal volume was calculated too low by the ventilators in the presence of leaks; the noninvasive ventilation algorithm was able to correct this difference in only 2 adult ventilators. No ventilator performed equally well under all tested conditions for all explored parameters. However, neonatal ventilators tended to perform better in the presence of leaks

  6. Energy and IAQ Implications of Residential Ventilation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Turner, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    This study evaluates the energy, humidity and indoor air quality (IAQ) implications of residential ventilation cooling in all U.S. IECC climate zones. A computer modeling approach was adopted, using an advanced residential building simulation tool with airflow, energy and humidity models. An economizer (large supply fan) was simulated to provide ventilation cooling while outdoor air temperatures were lower than indoor air temperatures (typically at night). The simulations were performed for a full year using one-minute time steps to allow for scheduling of ventilation systems and to account for interactions between ventilation and heating/cooling systems.

  7. Calculation of Industrial Enterprise Ventilation System by Network Integral Method

    Directory of Open Access Journals (Sweden)

    Mihienkova Evgeniya I.

    2016-01-01

    Full Text Available This paper describe a ventilation system calculation of the technology building industrial enterprise. On the basis of the calculation model for the enterprise offered technical decision of ventilation systems, subject to a compliance exchange multiplicity, purification efficiency, decontamination from the work area; provided the required volume of gas extraction from process equipment according to the sanitary standards and environmental requirements. Produced selection of ventilation equipment parameters, solved the problem of the air exchange balancing between ventilation systems to prevent the emergence of parasitic flows between the rooms building. SigmaNet software package was used for the implement the calculation.

  8. Patient Safety: Identifying and Managing Complications of Mechanical Ventilation.

    Science.gov (United States)

    Baid, Heather

    2016-12-01

    Mechanical ventilation is a fundamental aspect of critical care practice to help meet the respiratory needs of critically ill patients. Complications can occur though, as a direct result of being mechanically ventilated, or indirectly because of a secondary process. Preventing, identifying, and managing these complications significantly contribute to the role and responsibilities of critical care nurses in promoting patient safety. This article reviews common ventilator-associated events, including both infectious (eg, ventilator-associated pneumonia) and noninfectious causes (eg, acute respiratory distress syndrome, pulmonary edema, pleural effusion, and atelectasis). Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  9. Narrative review: ventilator-induced respiratory muscle weakness.

    Science.gov (United States)

    Tobin, Martin J; Laghi, Franco; Jubran, Amal

    2010-08-17

    Clinicians have long been aware that substantial lung injury results when mechanical ventilation imposes too much stress on the pulmonary parenchyma. Evidence is accruing that substantial injury may also result when the ventilator imposes too little stress on the respiratory muscles. Through adjustment of ventilator settings and administration of pharmacotherapy, the respiratory muscles may be rendered almost (or completely) inactive. Research in animals has shown that diaphragmatic inactivity produces severe injury and atrophy of muscle fibers. Human data have recently revealed that 18 to 69 hours of complete diaphragmatic inactivity associated with mechanical ventilation decreased the cross-sectional areas of diaphragmatic fibers by half or more. The atrophic injury seems to result from increased oxidative stress leading to activation of protein-degradation pathways. Scientific understanding of ventilator-induced respiratory muscle injury has not reached the stage where meaningful controlled trials can be done, and thus, it is not possible to give concrete recommendations for patient management. In the meantime, clinicians are advised to select ventilator settings that avoid both excessive patient effort and excessive respiratory muscle rest. The contour of the airway pressure waveform on a ventilator screen provides the most practical indication of patient effort, and clinicians are advised to pay close attention to the waveform as they titrate ventilator settings. Research on ventilator-induced respiratory muscle injury is in its infancy and portends to be an exciting area to follow.

  10. Demand controlled ventilation for multi-family dwellings

    DEFF Research Database (Denmark)

    Mortensen, Dorthe Kragsig

    for ventilation in residential buildings that depend on occupancy, pollutant emission, etc., and results in periods with poor air quality and/or unnecessary energy consumption. If the ventilation rate is varied according to the demand, the indoor climate can be improved and the energy consumption for ventilation...... specify desired levels of indoor air quality through ventilation rate requirements. The Danish Building Code requires a constant air flow rate equivalent to at least 0.5 air changes per hour in residential buildings. A constant air flow requirement is inconsistent with the time varying needs...

  11. Mechanical ventilation with heat recovery in cold climates

    DEFF Research Database (Denmark)

    Kragh, Jesper; Rose, Jørgen; Svendsen, Svend

    2005-01-01

    like the Northern Europe or in arctic climate like in Greenland or Alaska these ventilation systems will typically face problems with ice formation in the heat exchanger. When the warm humid room air comes in contact with the cold surfaces inside the exchanger (cooled by the outside air), the moisture......Building ventilation is necessary to achieve a healthy and comfortable indoor environment, but as energy prices continue to rise it is necessary to reduce the energy consumption. Using mechanical ventilation with heat recovery reduces the ventilation heat loss significantly, but in cold climates...

  12. Natural ventilation for the prevention of airborne contagion.

    Science.gov (United States)

    Escombe, A Roderick; Oeser, Clarissa C; Gilman, Robert H; Navincopa, Marcos; Ticona, Eduardo; Pan, William; Martínez, Carlos; Chacaltana, Jesus; Rodríguez, Richard; Moore, David A J; Friedland, Jon S; Evans, Carlton A

    2007-02-01

    Institutional transmission of airborne infections such as tuberculosis (TB) is an important public health problem, especially in resource-limited settings where protective measures such as negative-pressure isolation rooms are difficult to implement. Natural ventilation may offer a low-cost alternative. Our objective was to investigate the rates, determinants, and effects of natural ventilation in health care settings. The study was carried out in eight hospitals in Lima, Peru; five were hospitals of "old-fashioned" design built pre-1950, and three of "modern" design, built 1970-1990. In these hospitals 70 naturally ventilated clinical rooms where infectious patients are likely to be encountered were studied. These included respiratory isolation rooms, TB wards, respiratory wards, general medical wards, outpatient consulting rooms, waiting rooms, and emergency departments. These rooms were compared with 12 mechanically ventilated negative-pressure respiratory isolation rooms built post-2000. Ventilation was measured using a carbon dioxide tracer gas technique in 368 experiments. Architectural and environmental variables were measured. For each experiment, infection risk was estimated for TB exposure using the Wells-Riley model of airborne infection. We found that opening windows and doors provided median ventilation of 28 air changes/hour (ACH), more than double that of mechanically ventilated negative-pressure rooms ventilated at the 12 ACH recommended for high-risk areas, and 18 times that with windows and doors closed (p ventilation than modern naturally ventilated rooms (40 versus 17 ACH; p natural ventilation exceeded mechanical (p ventilated rooms 39% of susceptible individuals would become infected following 24 h of exposure to untreated TB patients of infectiousness characterised in a well-documented outbreak. This infection rate compared with 33% in modern and 11% in pre-1950 naturally ventilated facilities with windows and doors open. Opening windows and

  13. Mechanical ventilation in the acute respiratory distress syndrome.

    Science.gov (United States)

    Epelbaum, Oleg; Aronow, Wilbert S

    2017-08-01

    The management of the acute respiratory distress syndrome (ARDS) patient is fundamental to the field of intensive care medicine, and it presents unique challenges owing to the specialized mechanical ventilation techniques that such patients require. ARDS is a highly lethal disease, and there is compelling evidence that mechanical ventilation itself, if applied in an injurious fashion, can be a contributor to ARDS mortality. Therefore, it is imperative for any clinician central to the care of ARDS patients to understand the fundamental framework that underpins the approach to mechanical ventilation in this special scenario. The current review summarizes the major components of the mechanical ventilation strategy as it applies to ARDS.

  14. Experimental Investigation of Ventilation of a Surface Piercing Hydrofoil

    Science.gov (United States)

    Harwood, Casey; Miguel Montero, Francisco; Young, Yin Lu; Ceccio, Steven

    2013-11-01

    Bodies that pierce a liquid free-surface are prone to entrainment of atmospheric and/or vaporous gases. This process, called ventilation, can occur suddenly and violently, drastically altering hydrodynamic response. Experiments have been conducted at the free-surface towing-tank in the University of Michigan Marine Hydrodynamics Laboratory to investigate fully attached, partially ventilated, and fully ventilated flows around a canonical surface-piercing hydrofoil. The objectives of the work are: (i) to gain a broad and improved understanding of the physics of ventilation, (ii) to classify the physical mechanisms by which ventilation inception and washout may occur and quantify the conditions required for each mechanism and (iii) to quantify the effects of ventilation on global hydrodynamic responses, including the six force and moment components. Experimental data and high-speed video will be used to illustrate the impact of ventilation on hydrodynamic loads, pressures, and flow structures. The completion of this study is expected to contribute significantly toward a comprehensive understanding of ventilation physics, and toward an improved ability to design safe and controllable ventilated lifting surfaces for use in propulsion, energy harvesting, and turbomachinery. Supported by: The Office of Naval Research (ONR) (Grant No. N00014-09-1-1204); the National Research Foundation of Korea (NRF) (GCRC-SOP Grant No. 2012-0004783); the National Science Foundation Graduate Student Research Fellowship (Grant No. DGE 1256260).

  15. A taxonomy for mechanical ventilation: 10 fundamental maxims.

    Science.gov (United States)

    Chatburn, Robert L; El-Khatib, Mohamad; Mireles-Cabodevila, Eduardo

    2014-11-01

    The American Association for Respiratory Care has declared a benchmark for competency in mechanical ventilation that includes the ability to "apply to practice all ventilation modes currently available on all invasive and noninvasive mechanical ventilators." This level of competency presupposes the ability to identify, classify, compare, and contrast all modes of ventilation. Unfortunately, current educational paradigms do not supply the tools to achieve such goals. To fill this gap, we expand and refine a previously described taxonomy for classifying modes of ventilation and explain how it can be understood in terms of 10 fundamental constructs of ventilator technology: (1) defining a breath, (2) defining an assisted breath, (3) specifying the means of assisting breaths based on control variables specified by the equation of motion, (4) classifying breaths in terms of how inspiration is started and stopped, (5) identifying ventilator-initiated versus patient-initiated start and stop events, (6) defining spontaneous and mandatory breaths, (7) defining breath sequences (8), combining control variables and breath sequences into ventilatory patterns, (9) describing targeting schemes, and (10) constructing a formal taxonomy for modes of ventilation composed of control variable, breath sequence, and targeting schemes. Having established the theoretical basis of the taxonomy, we demonstrate a step-by-step procedure to classify any mode on any mechanical ventilator. Copyright © 2014 by Daedalus Enterprises.

  16. Instrumentation Design and Development Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — RTTC has facilities for design, development and fabrication of: custominstrumentation, mobile instrumentation, miniaturized instrumentation, wirelessinstrumentation,...

  17. Patient experiences during awake mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Danille Prime

    2016-02-01

    Full Text Available Background: Sedation practices in an ICU have shifted significantly in the past 20 years toward the use of minimizing sedation in mechanically ventilated patients. While minimizing sedation is clearly in the best interest of patients, data are lacking about how this approach affects patients’ experiences. Methods: We interviewed mechanically ventilated patients receiving minimal sedation, over a 6-month period in an ICU, in order to explore their emotional, comfort, and communication experiences. Their responses were compared with the responses of their available family members regarding their attitudes and perceptions of the patients’ experiences. Results: Seventy-five percent of the patients agreed or strongly agreed that they experienced pain, and 50% agreed or strongly agreed that they were comfortable. Half of the patients agreed or strongly agreed that they preferred to be kept awake. Five patients (31% indicated that they were frustrated while 17 relatives (89% agreed or strongly agreed that the patients were frustrated. When controlling for age and gender of respondents, family members perceived higher levels of patient pain (least square [LS] mean [95% CI]: 4.2 [3.7, 4.7] vs. 3.1 [2.5, 3.8]; p=0.022, frustration (LS mean [95% CI]: 4.2 [3.7, 4.6] vs. 3.2 [2.6, 3.9]; p=0.031, and adequate communication with nurses and doctors (LS mean [95% CI]: 3.9 [3.5, 4.4] vs. 3.1 [2.4, 3.7]; p=0.046 than the patients themselves. Conclusion: Patients tolerated minimal sedation without significant frustration while mechanically ventilated despite experiencing discomfort. Patient and family member perceptions of the patient experience may differ, especially in regards to pain and frustration. The use of a communication tool can facilitate understanding of patient experiences and preferences.

  18. Influences of Duration of Inspiratory Effort, Respiratory Mechanics, and Ventilator Type on Asynchrony With Pressure Support and Proportional Assist Ventilation.

    Science.gov (United States)

    Vasconcelos, Renata S; Sales, Raquel P; Melo, Luíz H de P; Marinho, Liégina S; Bastos, Vasco Pd; Nogueira, Andréa da Nc; Ferreira, Juliana C; Holanda, Marcelo A

    2017-05-01

    Pressure support ventilation (PSV) is often associated with patient-ventilator asynchrony. Proportional assist ventilation (PAV) offers inspiratory assistance proportional to patient effort, minimizing patient-ventilator asynchrony. The objective of this study was to evaluate the influence of respiratory mechanics and patient effort on patient-ventilator asynchrony during PSV and PAV plus (PAV+). We used a mechanical lung simulator and studied 3 respiratory mechanics profiles (normal, obstructive, and restrictive), with variations in the duration of inspiratory effort: 0.5, 1.0, 1.5, and 2.0 s. The Auto-Trak system was studied in ventilators when available. Outcome measures included inspiratory trigger delay, expiratory trigger asynchrony, and tidal volume (VT). Inspiratory trigger delay was greater in the obstructive respiratory mechanics profile and greatest with a effort of 2.0 s (160 ms); cycling asynchrony, particularly delayed cycling, was common in the obstructive profile, whereas the restrictive profile was associated with premature cycling. In comparison with PSV, PAV+ improved patient-ventilator synchrony, with a shorter triggering delay (28 ms vs 116 ms) and no cycling asynchrony in the restrictive profile. VT was lower with PAV+ than with PSV (630 mL vs 837 mL), as it was with the single-limb circuit ventilator (570 mL vs 837 mL). PAV+ mode was associated with longer cycling delays than were the other ventilation modes, especially for the obstructive profile and higher effort values. Auto-Trak eliminated automatic triggering. Mechanical ventilation asynchrony was influenced by effort, respiratory mechanics, ventilator type, and ventilation mode. In PSV mode, delayed cycling was associated with shorter effort in obstructive respiratory mechanics profiles, whereas premature cycling was more common with longer effort and a restrictive profile. PAV+ prevented premature cycling but not delayed cycling, especially in obstructive respiratory mechanics profiles

  19. Sterilization of endoscopic instruments.

    Science.gov (United States)

    Sabnis, Ravindra B; Bhattu, Amit; Vijaykumar, Mohankumar

    2014-03-01

    Sterilization of endoscopic instruments is an important but often ignored topic. The purpose of this article is to review the current literature on the sterilization of endoscopic instruments and elaborate on the appropriate sterilization practices. Autoclaving is an economic and excellent method of sterilizing the instruments that are not heat sensitive. Heat sensitive instruments may get damaged with hot sterilization methods. Several new endoscopic instruments such as flexible ureteroscopes, chip on tip endoscopes, are added in urologists armamentarium. Many of these instruments are heat sensitive and hence alternative efficacious methods of sterilization are necessary. Although ethylene oxide and hydrogen peroxide are excellent methods of sterilization, they have some drawbacks. Gamma irradiation is mainly for disposable items. Various chemical agents are widely used even though they achieve high-level disinfection rather than sterilization. This article reviews various methods of endoscopic instrument sterilization with their advantages and drawbacks. If appropriate sterilization methods are adopted, then it not only will protect patients from procedure-related infections but prevent hypersensitive allergic reactions. It will also protect instruments from damage and increase its longevity.

  20. Creating a Super Instrument

    DEFF Research Database (Denmark)

    Kallionpää, Maria; Gasselseder, Hans-Peter

    2015-01-01

    traditionally been dependent on their existing instrumental skills, various technological solutions can be used to reach beyond them. This paper focuses on the possibilities of enhancing composers' and performing pianists' technical and expressive vocabulary in the context of electroacoustic super instrument...

  1. Elective high frequency oscillatory ventilation versus conventional ventilation for acute pulmonary dysfunction in preterm infants

    NARCIS (Netherlands)

    Henderson-Smart, D. J.; Cools, F.; Bhuta, T.; Offringa, M.

    2007-01-01

    BACKGROUND: Respiratory failure due to lung immaturity is a major cause of mortality in preterm infants. Although the use of intermittent positive pressure ventilation (IPPV) in neonates with respiratory failure saves lives, its use is associated with lung injury and chronic lung disease (CLD).

  2. Elective high frequency oscillatory ventilation versus conventional ventilation for acute pulmonary dysfunction in preterm infants

    NARCIS (Netherlands)

    Cools, Filip; Henderson-Smart, David J.; Offringa, Martin; Askie, Lisa M.

    2009-01-01

    Background Respiratory failure due to lung immaturity is a major cause of mortality in preterm infants. Although the use of intermittent positive pressure ventilation (IPPV) in neonates with respiratory failure saves lives, its use is associated with lung injury and chronic lung disease (CLD). A

  3. Solar ventilation: The use of solar chimneys for natural ventilation of buildings

    NARCIS (Netherlands)

    Macquoy, B.

    2011-01-01

    This paper is written for the TIDO-course AR0532 Smart & Bioclimatic Design Theory. A very old principle is the system of the solar chimney for ventilation, which in recent years has regained interests. This essay will explore the potentials of solar chimneys in a modern application.

  4. Noninvasive Positive Pressure Ventilation or Conventional Mechanical Ventilation for Neonatal Continuous Positive Airway Pressure Failure

    Directory of Open Access Journals (Sweden)

    Zohreh Badiee

    2014-01-01

    Full Text Available Background: The aim of this study was to assess the success rate of nasal intermittent positive pressure ventilation (NIPPV for treatment of continuous positive airway pressure (CPAP failure and prevention of conventional ventilation (CV in preterm neonates. Methods: Since November 2012 to April 2013, a total number of 55 consecutive newborns with gestational ages of 26-35 weeks who had CPAP failure were randomly assigned to one of the two groups. The NIPPV group received NIPPV with the initial peak inspiratory pressure (PIP of 16-20 cmH 2 O and frequency of 40-60 breaths/min. The CV group received PIP of 12-20 cmH 2 O and frequency of 40-60 breaths/min. Results: About 74% of newborns who received NIPPV for management of CPAP failure responded to NIPPV and did not need intubation and mechanical ventilation. Newborns with lower postnatal age at entry to the study and lower 5 min Apgar score more likely had NIPPV failure. In addition, treatment failure was higher in newborns who needed more frequent doses of surfactant. Duration of oxygen therapy was 9.28 days in CV group and 7.77 days in NIPPV group (P = 0.050. Length of hospital stay in CV group and NIPPV groups were 48.7 and 41.7 days, respectively (P = 0.097. Conclusions: NIPPV could decrease the need for intubation and mechanical ventilation in preterm infants with CPAP failure.

  5. Recommendations for mechanical ventilation of critically ill children from the Paediatric Mechanical Ventilation Consensus Conference (PEMVECC)

    NARCIS (Netherlands)

    Kneyber, Martin C. J.; de Luca, Daniele; Calderini, Edoardo; Jarreau, Pierre-Henri; Javouhey, Etienne; Lopez-Herce, Jesus; Hammer, Jurg; Macrae, Duncan; Markhorst, Dick G.; Medina, Alberto; Pons-Odena, Marti; Racca, Fabrizio; Wolf, Gerhard; Biban, Paolo; Brierley, Joe; Rimensberger, Peter C.

    2017-01-01

    Purpose: Much of the common practice in paediatric mechanical ventilation is based on personal experiences and what paediatric critical care practitioners have adopted from adult and neonatal experience. This presents a barrier to planning and interpretation of clinical trials on the use of specific

  6. Passive Smoking in a Displacement Ventilated Room

    DEFF Research Database (Denmark)

    Bjørn, Erik; Nielsen, Peter V.

    The aim of this research is to see if the displacement ventilation principle can protect a person from exposure to passive tobacco smoking. This is done by full-scale experiments with two breathing thermal manikins, smoke visualisations, and tracer gas measurements. In some situations, exhaled...... smoke will stratify in a certain height due to the vertical temperature gradient. This horizontal layer of exhaled tobacco smoke may lead to exposure. In other situations, the smoke is mixed into the upper zone, and the passive smoker is protected to some extent by the displacement principle...

  7. Computational Fluid Dynamics and Ventilation Airflow

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm

    2014-01-01

    Computational fluid dynamics (CFD) was first introduced in the ventilation industry in the 1970s. CFD has been increasingly used since then, as testified by the number of peer-reviewed articles, which was less than 10 per year in the 1990s, and which is now 60 to 70 per year. This article discusses...... the principle behind CFD, the development in numerical schemes and computer size since the 1970s. Special attention is given to the selection of the correct governing equations, to the understanding of low turbulent flow, to the selection of turbulence models, and to addressing situations with more steady...

  8. Guide to Closing and Conditioning Ventilated Crawlspaces

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, B.

    2013-01-01

    This how-to guide explains the issues and concerns with conventional ventilated crawlspaces and provides prescriptive measures for improvements that will create healthier and more durable spaces. The methods described in this guide are not the only acceptable ways to treat a crawlspace but represent a proven strategy that works in many areas of the United States. The designs discussed in this guide may or may not meet the local building codes and as such will need to be researched before beginning the project.

  9. [A comparison of leak compensation in six acute care ventilators during non-invasive ventilation].

    Science.gov (United States)

    Hu, X S; Wang, Y; Wang, Z T; Yan, P; Zhang, X G; Zhao, S F; Xie, F; Gu, H J; Xie, L X

    2017-02-12

    Objective: To compare the ability of leak compensation in 6 medical ventilators during non-invasive ventilation. Methods: Six medical ventilators were selected, including 3 non-invasive ventilators (V60, Flexo and Stellar150), and 3 invasive ventilators(Avea, Servo I and BellaVist). Using a lung simulator, the ability of leak compensation was evaluated during triggering and cycling in 2 respiratory mechanics conditions (high airway resistance condition and high elastance resistance condition), and each condition was performed under 2 PEEP levels (4, and 8 cmH(2)O, 1 mmHg=0.098 kPa) at 4 air leak level conditions (L0: 2-3 L/min, L1: 8-10 L/min, L2: 22-27 L/min, L3: 35-40 L/min). Results: In the high elastance resistance condition (L2, L3)with different leak levels, the number of auto-triggering and miss-triggering of the non-invasive ventilator Flexo was significantly less than those of the others (L2: 1, 1; L3: 1.67, 1.33, P L2: 2.33, 2.33; L3: 3.33, 3.33, P L1 leak levels and PEEP levels [ARDS, PEEP=4: (109.8±1.8) ms, (112.0±0.6) ms; ARDS, PEEP=8: (103.1±0.7) ms, (109.7±0.7) ms; COPD, PEEP=4: (207.3±1.1) ms, (220.8±1.1) ms; COPD, PEEP=8: (195.6±6.7) ms, (200.0±1.2) ms , P <0.01]. Stellar150 had the shortest trigger delay time in high airway resistance condition with PEEP 4 cmH(2)O and high leak level L3[(262.8±0.8) ms , P <0.01]. V60 had a good performance on trigger delay time in high elastance resistance condition with PEEP 4 and 8 cmH(2)O, and also was most stable in increasing leak levels. Conclusion: In high airway resistance and high elastance resistance conditions with different PEEP levels and leak levels, V60, Stellar150, Flexo and BellaVista ventilators could be synchronized, among which V60, Stellar150 and Flexo presented a good performance features in specific conditions.

  10. [Prevention Effect of Thymosin-alpha1 Aganist Early Ventilator-associated Pneumonia in Patients with Mechanical Ventilation].

    Science.gov (United States)

    Zhang, Song-song; Li, Kun; Wang, Yu-hui; Ye, Ba-ning; Pan, Yu; Shi, Xian-qing

    2015-11-01

    To investigate the preventive effects of thymosin-alpha1 against early ventilator-associated pneumonia (VAP) in the patients with mechanical ventilation. Fifty two patients with expectancy of mechanical ventilation over 48 h were divided into routine therapy group (n=26) and thymosin therapy group (n= 26) in random. The patients in routine therapy group were given intensive care unit (ICU) conventional treatment, and the patients in thymosin therapy group were given thymosin treatment additionally (1.6 mg subcutaneous injection, qd X 7 d). The incidence and occurrence time of VAP were observed, and the time of mechanical ventilation and ICU stay were recorded. The levels of CD3+, CD4+, CD4+ /CD8+ T lymphocyte, CD14+ mononuclear cell human leukocyte antigens-DR (CD14+ HLA-DR) and procalcitonin (PCT) were detected before mechanical ventilation and at the 3d and 7th d after mechanical ventilation. The base line including the level of immunologic function had no difference between the two groups (P>0.05). The incidence of VAP in thymosin therapy group was lower than that in routine therapy group, but it was not significant difference (P>0.05). The durations of machine ventilation and ICU stay in thymosin therapy group were shorter than those in routine therapy group (Pmechanical ventilation, thymosin therapy group achived higher levels of CD3+, CD4+, CD4+ /CD8+ T lymphocyte and CD14+ HLA-DR than routine therapy group did (Pmechanical ventilation.

  11. Experimental Study of Air Distribution and Ventilation Effectiveness in a Room with a Combination of Different Mechanical Ventilation and Heating/Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.; Simone, Angela; Krajcik, Michal

    2011-01-01

    Mixing and displacement ventilation are common systems in commercial buildings, while mixing ventilation is used in residential buildings. Displacement ventilation provides fresh air to the occupied zone in a more efficient way than mixing ventilation but it is important to know how well it works...

  12. A rational framework for selecting modes of ventilation.

    Science.gov (United States)

    Mireles-Cabodevila, Eduardo; Hatipoğlu, Umur; Chatburn, Robert L

    2013-02-01

    Mechanical ventilation is a life-saving intervention for respiratory failure and thus has become the cornerstone of the practice of critical care medicine. A mechanical ventilation mode describes the predetermined pattern of patient-ventilator interaction. In recent years there has been a dizzying proliferation of mechanical ventilation modes, driven by technological advances and market pressures, rather than clinical data. The comparison of these modes is hampered by the sheer number of combinations that need to be tested against one another, as well as the lack of a coherent, logical nomenclature that accurately describes a mode. In this paper we propose a logical nomenclature for mechanical ventilation modes, akin to biological taxonomy. Accordingly, the control variable, breath sequence, and targeting schemes for the primary and secondary breaths represent the order, family, genus, and species, respectively, for the described mode. To distinguish unique operational algorithms, a fifth level of distinction, termed variety, is utilized. We posit that such coherent ordering would facilitate comparison and understanding of modes. Next we suggest that the clinical goals of mechanical ventilation may be simplified into 3 broad categories: provision of safe gas exchange; provision of comfort; and promotion of liberation from mechanical ventilation. Safety is achieved via optimization of ventilation-perfusion matching and pressure-volume relationship of the lungs. Comfort is provided by fostering patient-ventilator synchrony. Liberation is promoted by optimization of the weaning experience. Then we follow a paradigm that matches the technological capacity of a particular mode to achieving a specific clinical goal. Finally, we provide the reader with a comparison of existing modes based on these principles. The status quo in mechanical ventilation mode nomenclature impedes communication and comparison of existing mechanical ventilation modes. The proposed model

  13. Water Retention Capacity of Argillite from the VE Test - Phase II at Mont Terri: Effect of Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Fernandez, A. M.; Melon, A. M.

    2009-10-12

    The VE (ventilation) test carried out at the Mont Terri underground laboratory in Switzerland intended to evaluate in situ the behaviour of a consolidated clay formation when subjected to alternate periods of flow of wet and dry air during several months. For that, a 10-m gallery was excavated in the Opalinus Clay formation and carefully instrumented. Before and after a second ventilation phase boreholes were drilled. Samples were taken from the drill cores and were analysed from mineralogical and geochemical points of view. Also, the retention curves of these samples were determined in the laboratory following drying paths performed under free volume conditions at 20 degree centigrade, what is the content of this report. Although there are not large differences in the WRC of samples taken from different boreholes, at different distances from the gallery wall or before or after ventilation, those samples taken near the gallery wall and after ventilation tend to show a higher water retention capacity. This has been correlated to the higher salinity of the pore water of these samples, what increases their osmotic suction. This effect is attenuated towards high suctions. (Author) 10 refs.

  14. Andreas Vesalius' understanding of pulmonary ventilation.

    Science.gov (United States)

    Hage, J Joris; Brinkman, Romy J

    2016-09-01

    The historical evolution of understanding of the mechanical aspects of respiration is not well recorded. That the anatomist Andreas Vesalius (1515-1564) first recorded many of these mechanics in De Humani Corporis Fabrica Libri Septem has received little attention. We searched a digital copy of De Fabrica (1543) and its English translation as provided by Richardson and Carman (1998-2009) for references to aspects of pulmonary ventilation. We found that Vesalius grasped the essentials of tidal and forced respiration. He recognized that atmospheric pressure carried air into the lungs, approximately 100 years before Borelli did. He described an in vivo experiment of breathing, some 120 years before John Mayow produced his artificial model. He reported on positive pressure ventilation through a tracheotomy and on its life-saving effect, some 100 years before Robert Hook did. In publicly recording his insights over 450 years ago, Vesalius laid a firm basis for our understanding of the physiology of respiration and the management of its disorders. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Increasing natural ventilation using solar chimney

    Directory of Open Access Journals (Sweden)

    Nakielska Magdalena

    2017-01-01

    Full Text Available At a time when much attention is paid to the problem of energy saving is looking for new technical solutions, among others in the construction industry. At present, searching new solutions is a worldwide trend in creating buildings. Those solutions enable a comfortable use of building structures in harmony with natural environment and ensure reducing energy consumption. Solar chimneys, which facilitate the gravity ventilation by using solar energy, may be a solution to the problem. In hot climates solar chimney has been applied in the process of passive cooling of a building. In temperate zones and cold is used to assist natural ventilation. The problem of the solar chimney is not popular in Poland. Construction in Bydgoszcz two research positions, enabled the analysis of the impact of solar chimneys on the thermal comfort of rooms. This article presents experimental studies on solar chimney located in Poland. The analysis of the flow of air in the room during the day have been measured using two testmodels situated on the 3.1 building of UTP University of Science and Technology at 7 Kaliska street in Bydgoszcz.

  16. Music interventions for mechanically ventilated patients.

    Science.gov (United States)

    Bradt, Joke; Dileo, Cheryl

    2014-01-01

    Mechanical ventilation often causes major distress and anxiety in patients. The sensation of breathlessness, frequent suctioning, inability to talk, uncertainty regarding surroundings or condition, discomfort, isolation from others, and fear contribute to high levels of anxiety. Side effects of analgesia and sedation may lead to the prolongation of mechanical ventilation and, subsequently, to a longer length of hospitalization and increased cost. Therefore, non-pharmacological interventions should be considered for anxiety and stress management. Music interventions have been used to reduce anxiety and distress and improve physiological functioning in medical patients; however, their efficacy for mechanically ventilated patients needs to be evaluated. This review was originally published in 2010 and was updated in 2014. To update the previously published review that examined the effects of music therapy or music medicine interventions (as defined by the authors) on anxiety and other outcomes in mechanically ventilated patients. Specifically, the following objectives are addressed in this review.1. To conduct a meta-analysis to compare the effects of participation in standard care combined with music therapy or music medicine interventions with standard care alone.2. To compare the effects of patient-selected music with researcher-selected music.3. To compare the effects of different types of music interventions (e.g., music therapy versus music medicine). We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 2), MEDLINE (1950 to March 2014), CINAHL (1980 to March 2014), EMBASE (1980 to March 2014), PsycINFO (1967 to March 2014), LILACS (1982 to March 2014), Science Citation Index (1980 to March 2014), www.musictherapyworld.net (1 March 2008) (database is no longer functional), CAIRSS for Music (to March 2014), Proquest Digital Dissertations (1980 to March 2014), ClinicalTrials.gov (2000 to March 2014), Current

  17. The neonatal lung--physiology and ventilation.

    Science.gov (United States)

    Neumann, Roland P; von Ungern-Sternberg, Britta S

    2014-01-01

    This review article focuses on neonatal respiratory physiology, mechanical ventilation of the neonate and changes induced by anesthesia and surgery. Optimal ventilation techniques for preterm and term neonates are discussed. In summary, neonates are at high risk for respiratory complications during anesthesia, which can be explained by their characteristic respiratory physiology. Especially the delicate balance between closing volume and functional residual capacity can be easily disturbed by anesthetic and surgical interventions resulting in respiratory deterioration. Ventilatory strategies should ideally include application of an 'open lung strategy' as well avoidance of inappropriately high VT and excessive oxygen administration. In critically ill and unstable neonates, for example, extremely low-birthweight infants surgery in the neonatal intensive care unit might be an appropriate alternative to the operating theater. Best respiratory management of neonates during anesthesia is a team effort that should involve a joint multidisciplinary approach of anesthetists, pediatric surgeons, cardiologists, and neonatologists to reduce complications and optimize outcomes in this vulnerable population. © 2013 John Wiley & Sons Ltd.

  18. CDC releases ventilator-associated events criteria

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2017-01-01

    Full Text Available No abstract available. Article truncated at 150 words. A new term has been coined by the CDC, ventilator-associated events (VAEs (1. In 2011, the CDC convened a working group composed of members of several stakeholder organizations to address the limitations of the definition of ventilator-associated pneumonia (VAP definition (2. The organizations represented in the Working Group include: the Critical Care Societies Collaborative (the American Association of Critical-Care Nurses, the American College of Chest Physicians, the American Thoracic Society, and the Society for Critical Care Medicine; the American Association for Respiratory Care; the Association of Professionals in Infection Control and Epidemiology; the Council of State and Territorial Epidemiologists; the Healthcare Infection Control Practices Advisory Committee’s Surveillance Working Group; the Infectious Diseases Society of America; and the Society for Healthcare Epidemiology of America. VAEs are defined by an increase oxygen (>0.2 in FiO2 or positive end-expiratory pressure (PEEP (≥3 cm H2O, after a previous stable baseline of at least 2 …

  19. Instrumentation reference book

    CERN Document Server

    Boyes, Walt

    2002-01-01

    Instrumentation is not a clearly defined subject, having a 'fuzzy' boundary with a number of other disciplines. Often categorized as either 'techniques' or 'applications' this book addresses the various applications that may be needed with reference to the practical techniques that are available for the instrumentation or measurement of a specific physical quantity or quality. This makes it of direct interest to anyone working in the process, control and instrumentation fields where these measurements are essential.* Comprehensive and authoritative collection of technical information* Writte

  20. Impact of Different Ventilation Strategies on Driving Pressure, Mechanical Power, and Biological Markers During Open Abdominal Surgery in Rats

    NARCIS (Netherlands)

    Maia, Lígia de A.; Samary, Cynthia S.; Oliveira, Milena V.; Santos, Cintia L.; Huhle, Robert; Capelozzi, Vera L.; Morales, Marcelo M.; Schultz, Marcus J.; Abreu, Marcelo G.; Pelosi, Paolo; Silva, Pedro L.; Rocco, Patricia Rieken Macedo

    2017-01-01

    Intraoperative mechanical ventilation may yield lung injury. To date, there is no consensus regarding the best ventilator strategy for abdominal surgery. We aimed to investigate the impact of the mechanical ventilation strategies used in 2 recent trials (Intraoperative Protective Ventilation

  1. Effect of Ventilation Strategies on Residential Ozone Levels

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-08-01

    Elevated outdoor ozone levels are associated with adverse health effects. Because people spend the vast majority of their time indoors, reduction in indoor levels of ozone of outdoor origin would lower population exposures and might also lead to a reduction in ozone-associated adverse health effects. In most buildings, indoor ozone levels are diminished with respect to outdoor levels to an extent that depends on surface reactions and on the degree to which ozone penetrates the building envelope. Ozone enters buildings from outdoors together with the airflows that are driven by natural and mechanical means, including deliberate ventilation used to reduce concentrations of indoor-generated pollutants. When assessing the effect of deliberate ventilation on occupant health one should consider not only the positive effects on removing pollutants of indoor origin but also the possibility that enhanced ventilation might increase indoor levels of pollutants originating outdoors. This study considers how changes in residential ventilation that are designed to comply with ASHRAE Standard 62.2 might influence indoor levels of ozone. Simulation results show that the building envelope can contribute significantly to filtration of ozone. Consequently, the use of exhaust ventilation systems is predicted to produce lower indoor ozone concentrations than would occur with balanced ventilation systems operating at the same air-­exchange rate. We also investigated a strategy for reducing exposure to ozone that would deliberately reduce ventilation rates during times of high outdoor ozone concentration while still meeting daily average ventilation requirements.

  2. Reducing paediatric ventilator-associated pneumonia – a South ...

    African Journals Online (AJOL)

    There has been a decline in ventilator-associated pneumonia (VAP) in the paediatric intensive care units of developed countries. Previous studies at the Red Cross War Memorial Children's Hospital give an incidence of VAP of >40/1 000 ventilator days, identifying VAP as a priority area for practice improvement. We outline ...

  3. 30 CFR 57.14213 - Ventilation and shielding for welding.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 57.14213... welding. (a) Welding operations shall be shielded when performed at locations where arc flash could be hazardous to persons. (b) All welding operations shall be well-ventilated. ...

  4. 30 CFR 56.14213 - Ventilation and shielding for welding.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 56.14213... Equipment Safety Practices and Operational Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at locations where arc flash could be hazardous to...

  5. Uncertainties in different level assessments of domestic ventilation systems

    NARCIS (Netherlands)

    Bokel, R.M.J.; Yang, Z.; Cauberg, J.J.M.

    2013-01-01

    In order to improve the quality of ventilation systems, assessments are widely used. In this paper, 3 main assessment levels are distinguished based on the number of ventilation systems to be assessed and the assessment objective. The main assessment levels distinguished in this paper are global

  6. Investigation of Ventilation Strategies for the Day-Care Institutions

    DEFF Research Database (Denmark)

    Larsen, Olena Kalyanova; Afshari, Alireza; Heiselberg, Per

    2011-01-01

    Two existing nursery buildings, a mechanically and a naturally ventilated one, were chosen for investigations of energy saving potential and IAQ, using the different from present ventilation strategies and their control principles. These investigations are carried out applying a dynamic building ...

  7. Ventilation inhomogeneity in alpha1-antitrypsin-deficient emphysema

    NARCIS (Netherlands)

    Fregonese, L.; van Veen, H. P. A. A.; Sterk, P. J.; Stolk, J.

    2006-01-01

    The slope of phase III of the single-breath nitrogen wash-out test (sbN2-test) measures ventilation inhomogeneity and, in smokers, is strongly associated with small airways pathology. The present authors aimed to study ventilation inhomogeneity in emphysema related to type Z alpha1-antitrypsin (AAT)

  8. 9 CFR 354.226 - Lighting and ventilation.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Lighting and ventilation. 354.226 Section 354.226 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Facilities § 354.226 Lighting and ventilation. There shall be ample light, either natural or artificial or...

  9. Quantitative relationship of sick building syndrome symptoms with ventilation rates

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Mirer, Anna G.; Mendell, Mark J.

    2009-01-01

    Data from published studies were combined and analyzed to develop best-fit equations and curves quantifying the change in sick building syndrome (SBS) symptom prevalence in office workers with ventilation rate. For each study, slopes were calculated, representing the fractional change in SBS symptom prevalence per unit change in ventilation rate per person. Values of ventilation rate, associated with each value of slope, were also calculated. Linear regression equations were fitted to the resulting data points, after weighting by study size. Integration of the slope-ventilation rate equations yielded curves of relative SBS symptom prevalence versus ventilation rate. Based on these analyses, as the ventilation rate drops from 10 to 5 L/s-person, relative SBS symptom prevalence increases approximately 23percent (12percent to 32percent), and as ventilation rate increases from 10 to 25 L/s-person, relative prevalence decreases approximately 29percent (15percent to 42percent). Variations in SBS symptom types, building features, and outdoor air quality may cause the relationship ofSBS symptom prevalence with ventilation rate in specific situations to differ from the average relationship predicted in this paper.

  10. Energy Efficiency for Heating, Ventilating, Air-Conditioning Instructors.

    Science.gov (United States)

    Scharmann, Larry, Ed.; Lay, Gary, Ed.

    Intended primarily but not solely for use at the postsecondary level, this curriculum guide contains five units on energy efficiency that were designed to be incorporated into an existing program in heating, ventilating, and air-conditioning. The following topics are examined: how energy conservation pays, heating, ventilation, air-conditioning,…

  11. Natural ventilation in insect screened single span greenhouses ...

    African Journals Online (AJOL)

    Meanwhile the effect of ridge orientation, with respect to wind direction, on greenhouse ventilation was not obvious in terms of temperature or RH under inconsistent wind directions and low wind speeds. Greenhouse ventilation positively responded to low winds (0.25 m s-1) by reducing internal temperature as well as RH.

  12. One lung ventilation using double‑lumen tubes: Initial experience ...

    African Journals Online (AJOL)

    2014-05-09

    May 9, 2014 ... Background: One lung ventilation (OLV) is a technique routinely used in thoracic anesthesia to facilitate thoracic surgery. Double‑lumen tubes (DLT) remain the most popular and reliable choice for one lung ventilation especially in adult patients though use in Nigeria is limited. This study aimed to describe ...

  13. The effect of penetrating trunk trauma and mechanical ventilation on ...

    African Journals Online (AJOL)

    2010-10-08

    Oct 8, 2010 ... Controls. Fig. 3. Dynamometry results for lower limbs at 6 months after discharge (data expressed as means) (L = left; R = right; Quads = quadriceps muscle; Hams = hamstring muscle; *p<0.05; SV = mechanical ventilation <5 days; LV = mechanical ventilation ≥5 days). The effect.indd 30. 8/10/10 8:40:01 ...

  14. Experimental Investigation of Ventilation Efficiency in a Dentistry Surgical Room

    Directory of Open Access Journals (Sweden)

    Oladokun Majeed Olaide

    2016-01-01

    Full Text Available As a response to the need to provide an acceptable thermal comfort and air quality in indoor environments, various ventilation performance indicators were developed over the years. These metrics are mainly geared towards air distribution, heat and pollutant removals. Evidence exists of influencing factors on these indicators as centered on ventilation design and operations. Unlike other indoor environments, health care environment requires better performance of ventilation system to prevent an incidence of nosocomial and other hospital acquired illnesses. This study investigates, using in-situ experiments, the ventilation efficiency in a dentistry surgical room. Thermal and hygric parameters were monitored on the air terminal devices and occupied zone over a period of one week covering both occupied and unoccupied hours. The resulting time-series parameters were used to evaluate the room’s ventilation effectiveness. Also, the obtained parameters were benchmarked against ASHRAE 170 (2013 and MS1525 (2014 requirements for ventilation in health care environment and building energy efficiency respectively. The results show that the mean daily operative conditions failed to satisfy the provisions of both standards. Regarding effectiveness, the findings reveal that the surgical room ventilation is ineffective with ventilation efficiency values ranging between 0 and 0.5 indicating air distribution short-circuiting. These results suggest further investigations, through numerical simulation, on the effect of this short-circuiting on thermal comfort, infection risk assessments and possible design improvements, an endeavour that forms our next line of research inquiries.

  15. Novel bed integrated ventilation method for hospital patient rooms

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Melikov, Arsen Krikor; Kokora, Monika

    2014-01-01

    This study presents a novel method for advanced ventilation of hospital wards leading to improved air quality at reduced ventilation rate. The idea is to evacuate the bio-effluents generated from patients’ body by local exhaustion before being spread in the room. This concept was realized by usin...

  16. Validation of Boundary Conditions for CFD Simulations on Ventilated Rooms

    DEFF Research Database (Denmark)

    Topp, Claus; Jensen, Rasmus Lund; Pedersen, D.N.

    2001-01-01

    The application of Computational Fluid Dynamics (CFD) for ventilation research and design of ventilation systems has increased during the recent years. This paper provides an investigation of direct description of boundary conditions for a complex inlet diffuser and a heated surface. A series...

  17. Ventilation coefficient trends in the recent decades over four major ...

    Indian Academy of Sciences (India)

    The decreasing ventilation coefficient increased the ground level pollution thereby deteriorating the air quality for the urban population. For Mumbai and. Kolkata, decreasing mixing depths and decreasing wind speed contributed to the decreasing ventilation coefficient whereas for Delhi and Chennai decreasing wind speed ...

  18. Prediction of Length of Postoperative Ventilation in CDH Survivors ...

    African Journals Online (AJOL)

    Index Word: Congenital diaphragmatic hernia, Mechanical ventilation weaning, Endo-tracheal tube removal. ... the baby and according to the blood gases analyses, keeping PO2 levels .... room or the operation room, b: the baby could not be stabilized preoperatively without high frequency ventilation, c: significant patent.

  19. Mechanical ventilation drives inflammation in severe viral bronchiolitis.

    Directory of Open Access Journals (Sweden)

    Marije P Hennus

    Full Text Available INTRODUCTION: Respiratory insufficiency due to severe respiratory syncytial virus (RSV infection is the most frequent cause of paediatric intensive care unit admission in infants during the winter season. Previous studies have shown increased levels of inflammatory mediators in airways of mechanically ventilated children compared to spontaneous breathing children with viral bronchiolitis. In this prospective observational multi-center study we aimed to investigate whether this increase was related to disease severity or caused by mechanical ventilation. MATERIALS AND METHODS: Nasopharyngeal aspirates were collected <1 hour before intubation and 24 hours later in RSV bronchiolitis patients with respiratory failure (n = 18 and non-ventilated RSV bronchiolitis controls (n = 18. Concentrations of the following cytokines were measured: interleukin (IL-1α, IL-1β, IL-6, monocyte chemotactic protein (MCP-1 and macrophage inflammatory protein (MIP-1α. RESULTS: Baseline cytokine levels were comparable between ventilated and non-ventilated infants. After 24 hours of mechanical ventilation mean cytokine levels, except for MIP-1α, were elevated compared to non-ventilated infected controls: IL-1α (159 versus 4 pg/ml, p<0.01, IL-1β (1068 versus 99 pg/ml, p<0.01, IL-6 (2343 versus 958 pg/ml, p<0.05 and MCP-1 (174 versus 26 pg/ml, p<0.05. CONCLUSIONS: Using pre- and post-intubation observations, this study suggests that endotracheal intubation and subsequent mechanical ventilation cause a robust pulmonary inflammation in infants with RSV bronchiolitis.

  20. Intelligent ventilation in the intensive care unit | Sviri | Southern ...

    African Journals Online (AJOL)

    Objectives. Automated, microprocessor-controlled, closed-loop mechanical ventilation has been used in our Medical Intensive Care Unit (MICU) at the Hadassah Hebrew-University Medical Center for the past 15 years; for 10 years it has been the primary (preferred) ventilator modality. Design and setting. We describe our ...

  1. Amyotrophic Lateral Sclerosis Patients' Perspectives on Use of Mechanical Ventilation.

    Science.gov (United States)

    Young, Jenny M.; And Others

    1994-01-01

    Interviewed 13 amyotrophic lateral sclerosis patients. All believed that they alone should make decision regarding use of mechanical ventilation. Factors they considered important were quality of life, severity of disability, availability of ventilation by means of nasal mask, possible admission to long-term care facility, ability to discontinue…

  2. Non-invasive mechanical ventilation | Giles | Southern African ...

    African Journals Online (AJOL)

    Non-invasive ventilation (NIV) is a modality of providing airway and pulmonary support in both acute and chronic diseases of the lung. The method of mechanical ventilation without the use of an endotracheal tube was developed over a century ago, but its utility has only been explored recently with advances in technology.

  3. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation

    NARCIS (Netherlands)

    Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical

  4. Weaning from the ventilator in patients with respiratory failure

    NARCIS (Netherlands)

    B.W. van den Berg (Bart)

    1994-01-01

    textabstractWeaning from the ventilator is the gradual withdrawal of mechanical ventilatory support. Mechanical ventilation is well-accepted as rescue therapy in patients with life-threatening respiratory failure. As this treatment is associated with substantial morbidity and mortality, ventilatory

  5. Ventilation coefficient trends in the recent decades over four major ...

    Indian Academy of Sciences (India)

    A decreasing trend in ventilation coefficient is observed in all the four metros during the 30 years period indicating increasing pollution potential and a degradation in the air quality over these urban centers. In Delhi, the ventilation coefficient decreased at the rate of 49 and 32 m2/s/year in the months of December and ...

  6. Influence of old age on survival after prolonged mechanical ventilation

    NARCIS (Netherlands)

    Endeman, H.; Heeffer, L.; Holleman, F.; Westendorp, R. G. J.; Hoekstra, J. B. L.

    2005-01-01

    BACKGROUND: While the proportion of elderly people in society is increasing, little is known about the influence of old age on survival after prolonged mechanical ventilation. METHODS: A retrospective follow-up study of 120 patients who had been mechanically ventilated for at least 10 days was

  7. [Injury in air way of newborn with mechanical ventilation].

    Science.gov (United States)

    Flores-Nava, Gerardo; Mateos-Sánchez, Leovigildo; Jurado-Hernández, Víctor Hugo

    2008-01-01

    mechanical ventilation is used in all Neonatal Intensive Care Unit (NICU). The patients with more than a week with mechanical ventilation can develop complications in the airway. The diagnosis is carrying out with a bronchoscope. to determine the type of complications presented in a group of neonates who had received, one o more weeks, mechanical ventilation, through bronchoscopy. we realized a retrospective reviewed of the charts of patients with mechanical ventilation in a NICU during a one-year period and whom a bronchoscopy was carried out for respiratory distress after extubation. We analyzed; the type of lesion, age of gestation and birth weight, gender, mechanical ventilation days, atelectasis, age and days of extra uterine life in the moment of the bronchoscopy. In the variables we achieved frequency, averages, media and standard deviations. we reviewed 55 charts. The mean gestational age was 34 weeks, birth weight 2075 g and 38 days with mechanical ventilation. Male 52.7 %. Atelectasis in 78.7 %, a third of the patients required mechanical ventilation after extubation. The airway lesions were (%); bronchial stenosis 25.4, laryngotracheobronchitis 18.1, laryngeal edema 10.9, laryngotracheitis 7.2, laryngomalacia 7.2 %, ulcer 7.2, cord paralysis 5.4, granulom 3.6 and normal 3.6. Three required tracheotomy. subglotic stenosis was the complications more frequent. Ideally all the neonates after mechanical ventilation shoud realized a bronchoscopy for preventing complications.

  8. Air Distribution in Aircraft Cabins Using Free Convection Personalized Ventilation

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The aim of the ventilation system is to control cross infection in an aircraft cabin if one or a number of the passengers are “source patients” (source of airborne disease). The Personalized Ventilation described in this text is of the type mentioned in “Free Convection Personalized Ventilation”....

  9. Experimental study of diffuse ceiling ventilation in classroom

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Terkildsen, Søren

    Diffuse ceiling ventilation is a novel air distribution device that combines the suspended acoustic ceiling with ventilation supply. A diffuse ceiling distributes the supply air above the acoustic tiles and has proven performance in laboratory experiments. To study the performance in real...

  10. Reducing the ingress of urban noise through natural ventilation openings.

    Science.gov (United States)

    Oldham, D J; de Salis, M H; Sharples, S

    2004-01-01

    For buildings in busy urban areas affected by high levels of road traffic noise the potential to use natural ventilation can be limited by excessive noise entering through ventilation openings. This paper is concerned with techniques to reduce noise ingress into naturally ventilated buildings while minimizing airflow path resistance. A combined experimental and theoretical approach to the interaction of airflow and sound transmission through ventilators for natural ventilation applications is described. A key element of the investigation has been the development of testing facilities capable of measuring the airflow and sound transmission losses for a range of ventilation noise control strategies. It is demonstrated that a combination of sound reduction mechanisms -- one covering low frequency sound and another covering high frequency sound -- is required to attenuate effectively noise from typical urban sources. A method is proposed for quantifying the acoustic performance of different strategies to enable comparisons and informed decisions to be made leading to the possibility of a design methodology for optimizing the ventilation and acoustic performance of different strategies. The need for employing techniques for combating low frequency sound in tandem with techniques for reducing high frequency sound in reducing the ingress of noise from urban sources such as road traffic to acceptable levels is demonstrated. A technique is proposed for enabling the acoustic and airflow performance of apertures for natural ventilation systems to be designed simultaneously.

  11. Natural ventilation of large multi-span greenhouses

    NARCIS (Netherlands)

    Jong, de T.

    1990-01-01

    In this thesis the ventilation of large multi-span greenhouses caused by wind and temperature effects is studied. Quantification of the ventilation is important to improve the control of the greenhouse climate.

    Knowledge of the flow characteristics of the one-side-mounted windows of

  12. NATURAL BASEMENT VENTILATION AS A RADON MITIGATION TECHNIQUE

    Science.gov (United States)

    The report documents a study of natural basement ventilation in two research houses during both the summer cooling season and the winter heating season. NOTE: Natural basement ventilation has always been recommended as a way to reduce radon levels in houses. However, its efficacy...

  13. [Hypercapnic respiratory failure. Pathophysiology, indications for mechanical ventilation and management].

    Science.gov (United States)

    Kreppein, U; Litterst, P; Westhoff, M

    2016-04-01

    Acute hypercapnic respiratory failure is mostly seen in patients with chronic obstructive pulmonary disease (COPD) and obesity hypoventilation syndrome (OHS). Depending on the underlying cause it may be associated with hypoxemic respiratory failure and places high demands on mechanical ventilation. Presentation of the current knowledge on indications and management of mechanical ventilation in patients with hypercapnic respiratory failure. Review of the literature. Important by the selection of mechanical ventilation procedures is recognition of the predominant pathophysiological component. In hypercapnic respiratory failure with a pH ventilation (NIV) is primarily indicated unless there are contraindications. In patients with severe respiratory acidosis NIV requires a skilled and experienced team and close monitoring in order to perceive a failure of NIV. In acute exacerbation of COPD ventilator settings need a long expiration and short inspiration time to avoid further hyperinflation and an increase in intrinsic positive end-expiratory pressure (PEEP). Ventilation must be adapted to the pathophysiological situation in patients with OHS or overlap syndrome. If severe respiratory acidosis and hypercapnia cannot be managed by mechanical ventilation therapy alone extracorporeal venous CO2 removal may be necessary. Reports on this approach in awake patients are available. The use of NIV is the predominant treatment in patients with hypercapnic respiratory failure but close monitoring is necessary in order not to miss the indications for intubation and invasive ventilation. Methods of extracorporeal CO2 removal especially in awake patients need further evaluation.

  14. Enhanced Single-Sided Ventilation with Overhang in Buildings

    Directory of Open Access Journals (Sweden)

    Jinsoo Park

    2016-02-01

    Full Text Available Enhancing the ventilation performance of energy-efficient buildings with single-sided openings is important because their ventilation performance is poor and strongly depends on the wind conditions. We considered an overhang as a potential building façade for improving the single-sided ventilation performance. We performed numerical simulations of three-dimensional unsteady turbulent flows over an idealized building with an overhang in order to investigate the effect of the overhang on the ventilation performance. Parametric studies were systematically carried out where the overhang length, wind speed, and wind direction were varied. The numerical results showed that the overhang drastically enhanced the ventilation rate in the windward direction regardless of the wind speed. This is because, for windward cases, the overhang produces a vortex with strong flow separation near the tip of the overhang, which promotes a net airflow exchange at the entrance and increases the ventilation rate. However, the ventilation rates for the leeward and side cases are slightly decreased with the overhang. Using an overhang with single-sided ventilation greatly reduces the local mean age of air (LMA in the windward direction but increases it in the leeward direction.

  15. Go with the Flow: Principles and examples of natural ventilation

    NARCIS (Netherlands)

    Van Agtmaal, B.

    2011-01-01

    This "designers' manual" is made during the TIDO-course AR0531 Smart & Bioclimatic Design. With an increasing need for more sustainable buildings, natural ventilation presents us with a low-energy and low-cost solution. This manual inspires designers to apply natural ventilation, by offering

  16. [The study of noninvasive ventilator impeller based on ANSYS].

    Science.gov (United States)

    Hu, Zhaoyan; Lu, Pan; Xie, Haiming; Zhou, Yaxu

    2011-06-01

    An impeller plays a significant role in the non-invasive ventilator. This paper shows a model of impeller for noninvasive ventilator established with the software Solidworks. The model was studied for feasibility based on ANSYS. Then stress and strain of the impeller were discussed under the external loads. The results of the analysis provided verification for the reliable design of impellers.

  17. High-frequency oscillatory ventilation — a clinical approach

    African Journals Online (AJOL)

    Nicky

    Pediatric Critical Care Medicine, Duke University Children's Hospital, Durham, North. Carolina ... ventilation emerged. Studies during the 1970s clearly demonstrated in animal models of acute lung injury that adequate alveolar ventilation could be achieved with tidal ... exchange mechanism during HFOV was caused by the.

  18. Chair with Integrated Personalized Ventilation for Minimizing Cross Infection

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Bartholomaeussen, Niels Møller; Jakubowska, Ewa

    2007-01-01

    Normally we protect ourselves from cross infection by supplying fresh air to a room by a diffuser, and this air is distributed in the room according to different principles as: mixing ventilation, displacement ventilation, etc. That means that it is necessary to supply a very large amount of air ...

  19. Bed with Integrated Personalized Ventilation for Minimizing Cross Infection

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jiang, Hao; Polak, Marcin

    2007-01-01

    Normally we protect ourselves from cross infection by supplying fresh air to a room by a diffuser. This air is then distributed in the room according to different principles as e.g. mixing ventilation, displacement ventilation, etc. That means that it is necessary to supply a very large amount of...

  20. Continuous use of an adaptive lung ventilation controller in critically ...

    African Journals Online (AJOL)

    1995-05-05

    May 5, 1995 ... Adaptive lung ventilation (ALV) refers to closed-loop mechanical ventilation designed to work in paralysed as well as spontaneously breathing patients, enabling variable ventilatory support as required, breath by breath, in each individual patient.',2. The ALV controller utilises pressure-controlled.