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William J Fisk - One of the best experts on this subject based on the ideXlab platform.
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Quantification of the association of Ventilation Rates with sick building syndrome symptoms
2009Co-Authors: William J Fisk, Anna G. Mirer, Mark J MendellAbstract: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 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 fit 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, relative SBS symptom prevalence increases approximately 23percent (12percent to 32percent) as the Ventilation Rate drops from 10 to 5 L/s-person and relative prevalence decreases approximately 29percent (15percent to 42percent) as Ventilation Rate increases from 10 to 25 L/s-person.
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Quantitative relationship of sick building syndrome symptoms with Ventilation Rates
Indoor air, 2009Co-Authors: William J Fisk, Anna G. Mirer, Mark J MendellAbstract: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 23% (12% to 32%), and as Ventilation Rate increases from 10 to 25 L/s-person, relative prevalence decreases approximately 29% (15% to 42%). Variations in SBS symptom types, building features, and outdoor air quality may cause the relationship of SBS symptom prevalence with Ventilation Rate in specific situations to differ from the average relationship predicted in this paper.
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economizer system cost effectiveness accounting for the influence of Ventilation Rate on sick leave
Lawrence Berkeley National Laboratory, 2003Co-Authors: William J Fisk, Olli Seppanen, David Faulkner, Joe HuangAbstract:This study estimated the health, energy, and economic benefits of an economizer Ventilation control system that increases outside air supply during mild weather to save energy. A model of the influence of Ventilation Rate on airborne transmission of respiratory illnesses was used to extend the limited data relating Ventilation Rate with illness and sick leave. An energy simulation model calculated Ventilation Rates and energy use versus time for an office building in Washington, DC with fixed minimum outdoor air supply Rates, with and without an economizer. Sick leave Rates were estimated with the disease transmission model. In the modeled 72-person office building, our analyses indicate that the economizer reduces energy costs by approximately $2000 and, in addition, reduces sick leave. The financial benefit of the decrease in sick leave is estimated to be between $6,000 and $16,000. This modelling suggests that economizers are much more cost effective than currently recognized.
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effect of outside air Ventilation Rate on volatile organic compound concentrations in a call center
Atmospheric Environment, 2003Co-Authors: Alfred T Hodgson, David Faulkner, D.l. Dibartolomeo, D P Sullivan, Marion L Russell, William J FiskAbstract:Abstract A study of the relationship between outside air Ventilation Rate and concentrations of volatile organic compounds (VOCs) geneRated indoors was conducted in a call center office building. The building, with two floors and a total floor area of 4600 m 2 , is located in the San Francisco Bay Area, CA. Ventilation Rates were manipulated with the building's four air handling units (AHUs). VOC and CO 2 concentrations in the AHU returns were measured on 7 days during a 13-week period. VOC emission factors were determined for individual zones on days when they were operating at near steady-state conditions. The emission factor data were subjected to principal component (PC) analysis to identify groups of co-varying compounds. Potential sources of the PC vectors were ascribed based on information from the literature. The per occupant CO 2 generation Rates were 0.0068–0.0092 l s −1 . The per occupant isoprene generation Rates of 0.2–0.3 mg h −1 were consistent with the value predicted by mass balance from breath concentration and exhalation Rate. The relationships between indoor minus outdoor VOC concentrations and Ventilation Rate were qualitatively examined for eight VOCs. Of these, acetaldehyde and hexanal, which likely were associated with material sources, and decamethylcyclopentasiloxane, associated with personal care products, exhibited general trends of higher concentrations at lower Ventilation Rates. For other compounds, a clear inverse relationship between VOC concentrations and Ventilation was not observed. The net concentration of 2,2,4-trimethyl-1,3-pentanediol monoisobutyRate isomers, examples of low-volatility compounds, changed very little with Ventilation likely due to sorption and re-emission effects. These results illustRate that the efficacy of Ventilation for controlling VOC concentrations can vary considerably depending upon the operation of the building, the pollutant sources and the physical and chemical processes affecting the pollutants. Thus, source control measures, in addition to adequate Ventilation, are required to limit concentrations of VOCs in office buildings.
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Worker productivity and Ventilation Rate in a call center: Analyses of time-series data for a group of workers
2002Co-Authors: William J Fisk, David Faulkner, Phillip N. Price, Douglas P. Sullivan, D.l. Dibartolomeo, C. C. Federspiel, G. Liu, Maureen LahiffAbstract:In previous studies, increased Ventilation Rates and reduced indoor carbon dioxide concentrations have been associated with improvements in health at work and increased performance in work-related tasks. Very few studies have assessed whether Ventilation Rates influence performance of real work. This paper describes part one of a two-part analysis from a productivity study performed in a call center opeRated by a health maintenance organization. Outside air Ventilation Rates were manipulated, indoor air temperatures, humidities, and carbon dioxide concentrations were monitored, and worker performance data for advice nurses, with 30-minute resolution, were analyzed via multivariate linear regression to look for an association of performance with building Ventilation Rate, or with indoor carbon dioxide concentration (which is related to Ventilation Rate per worker). Results suggest that the effect of Ventilation Rate on worker performance in this call center was very small (probably less than 1%) or nil, over most of the range of Ventilation Rate experienced during the study (roughly 12 L s{sup -1} to 48 L s{sup -1} per person). However, there is some evidence suggesting performance improvements of 2% or more when the Ventilation Rate per person is very high, as indicated by indoor CO{sub 2} concentrations exceeding outdoor concentrations by less than 75 ppm.
Mohamud Daya - One of the best experts on this subject based on the ideXlab platform.
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the impact of Ventilation Rate on end tidal carbon dioxide level during manual cardiopulmonary resuscitation
Resuscitation, 2020Co-Authors: Sofia Ruiz De Gauna, James K. Russell, J J Gutierrez, Jesus Ruiz, Mikel Leturiondo, Izaskun Azcarate, Digna M Gonzalezotero, Carlos Corcuera, Mohamud DayaAbstract:Abstract Aim Ventilation Rate is a confounding factor for interpretation of end-tidal carbon dioxide (ETCO2) during cardiopulmonary resuscitation (CPR). The aim of our study was to model the effect of Ventilation Rate on ETCO2 during manual CPR in adult out-of-hospital cardiac arrest (OHCA). Methods We conducted a retrospective analysis of OHCA monitor-defibrillator files with concurrent capnogram, compression depth, transthoracic impedance and ECG. We annotated pairs of capnogram segments presenting differences in average Ventilation Rate and average ETCO2 value but with other influencing factors (e.g. compression Rate and depth) presenting similar values within the pair. ETCO2 variation as a function of Ventilation Rate was adjusted through curve fitting using non-linear least squares as a measure of goodness of fit. Results A total of 141 pairs of segments from 102 patients were annotated. Each pair provided a single data point for curve fitting. The best goodness of fit yielded a coefficient of determination R2 of 0.93. Our model described that ETCO2 decays exponentially with increasing Ventilation Rate. The model showed no differences attributable to the airway type (endotracheal tube or supraglottic King-LT-D). Conclusion Capnogram interpretation during CPR is challenging since many factors influence ETCO2. For adequate interpretation, we need to know the effect of each factor on ETCO2. Our model allows quantifying the effect of Ventilation Rate on ETCO2 variation. Our findings could contribute to better interpretation of ETCO2 during CPR.
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abstract 436 Ventilation Rate impact on end tidal carbon dioxide levels during manual cardiopulmonary resuscitation
Circulation, 2019Co-Authors: Jesus Ruiz, James K. Russell, Sofia Ruiz De Gauna, J J Gutierrez, Mikel Leturiondo, Carlos Corcuera, L A Leturiondo, Mohamud DayaAbstract:Introduction: End-tidal carbon dioxide (ETCO2) levels during cardiopulmonary resuscitation (CPR) depend primarily on the blood flow geneRated by chest compressions, on the Ventilation Rate and on t...
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Feasibility of the capnogram to monitor Ventilation Rate during cardiopulmonary resuscitation.
Resuscitation, 2016Co-Authors: Elisabete Aramendi, Andoni Elola, Erik Alonso, Unai Irusta, Mohamud Daya, James K. Russell, Pia Hubner, Fritz SterzAbstract:Abstract Aim The Rates of chest compressions (CCs) and Ventilations are both important metrics to monitor the quality of cardiopulmonary resuscitation (CPR). Capnography permits monitoring Ventilation, but the CCs provided during CPR corrupt the capnogram and compromise the accuracy of automatic Ventilation detectors. The aim of this study was to evaluate the feasibility of an automatic algorithm based on the capnogram to detect Ventilations and provide feedback on Ventilation Rate during CPR, specifically addressing intervals where CCs are delivered. Methods The dataset used to develop and test the algorithm contained in-hospital and out-of-hospital cardiac arrest episodes. The method relies on adaptive thresholding to detect Ventilations in the first derivative of the capnogram. The performance of the detector was reported in terms of sensitivity (SE) and Positive Predictive Value (PPV). The overall performance was reported in terms of the Rate error and errors in the hyperVentilation alarms. Results were given sepaRately for the intervals with CCs. Results A total of 83 episodes were considered, resulting in 4880min and 46,740 Ventilations (8741 during CCs). The method showed an overall SE/PPV above 99% and 97% respectively, even in intervals with CCs. The error for the Ventilation Rate was below 1.8min −1 in any group, and >99% of the Ventilation alarms were correctly detected. Conclusion A method to provide accuRate feedback on Ventilation Rate using only the capnogram is proposed. Its accuracy was proven even in intervals where canpography signal was severely corrupted by CCs. This algorithm could be integRated into monitor/defibrillators to provide reliable feedback on Ventilation Rate during CPR.
Mark J Mendell - One of the best experts on this subject based on the ideXlab platform.
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evaluation of the indoor air quality minimum Ventilation Rate procedure for use in california retail buildings
Indoor Air, 2015Co-Authors: S M Dutton, D P Sullivan, Mark J Mendell, Wanyu R Chan, M Barrios, Meera Sidheswaran, Ekaterina A Eliseeva, W J FiskAbstract:This research assesses benefits of adding to California Title-24 Ventilation Rate (VR) standards a performance-based option, similar to the American Society of Heating, Refrigerating, and Air Conditioning Engineers ‘Indoor Air Quality Procedure’ (IAQP) for retail spaces. Ventilation Rates and concentrations of contaminants of concern (CoC) were measured in 13 stores. Mass balance models were used to estimate ‘IAQP-based’ VRs that would maintain concentrations of all CoCs below health- or odor-based reference concentration limits. An intervention study in a ‘big box’ store assessed how the current VR, the Title 24-prescribed VR, and the IAQP-based VR (0.24, 0.69, and 1.51 air changes per hour) influenced measured IAQ and perceived of IAQ. Neither current VRs nor Title 24-prescribed VRs would maintain all CoCs below reference limits in 12 of 13 stores. In the big box store, the IAQP-based VR kept all CoCs below limits. More than 80% of subjects reported acceptable air quality at all three VRs. In 11 of 13 buildings, saving energy through lower VRs while maintaining acceptable IAQ would require source reduction or gas-phase air cleaning for CoCs. In only one of the 13 retail stores surveyed, application of the IAQP would have allowed reduced VRs without additional contaminant-reduction stRategies.
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Quantification of the association of Ventilation Rates with sick building syndrome symptoms
2009Co-Authors: William J Fisk, Anna G. Mirer, Mark J MendellAbstract: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 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 fit 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, relative SBS symptom prevalence increases approximately 23percent (12percent to 32percent) as the Ventilation Rate drops from 10 to 5 L/s-person and relative prevalence decreases approximately 29percent (15percent to 42percent) as Ventilation Rate increases from 10 to 25 L/s-person.
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Quantitative relationship of sick building syndrome symptoms with Ventilation Rates
Indoor air, 2009Co-Authors: William J Fisk, Anna G. Mirer, Mark J MendellAbstract: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 23% (12% to 32%), and as Ventilation Rate increases from 10 to 25 L/s-person, relative prevalence decreases approximately 29% (15% to 42%). Variations in SBS symptom types, building features, and outdoor air quality may cause the relationship of SBS symptom prevalence with Ventilation Rate in specific situations to differ from the average relationship predicted in this paper.
Hiroshi Akasaka - One of the best experts on this subject based on the ideXlab platform.
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The effects of human behavior on natural Ventilation Rate and indoor air environment in summer − a field study in southern Japan
Energy and Buildings, 1997Co-Authors: Go Iwashita, Hiroshi AkasakaAbstract:Abstract Residents completed a questionnaire survey assessing indoor environment and residents' behavior (i.e. when they opened windows/doors, when they opeRated air conditioners, and so on) during the period of Ventilation measurement. The purpose of this study is to measure the Ventilation Rate in occupied dwellings in Kagoshima City, located in the southern part of Japan, using the tracer gas method and to investigate the relationship between the occupants' behavior in each dwelling and the energy consumption for air conditioning during the summer period. Based on the continuous measurement of the Ventilation Rate in eight dwellings, the proportion between the total Ventilation Rate (Ventilation Rate during occupancy of the dwellings) and the basic Ventilation Rate (Ventilation Rate during non-occupancy and with door/windows closed) is discussed. The measuring principle applied is the constant concentration tracer gas method. The main conclusion is that there is a large difference between the mean basic Ventilation Rate and the mean total Ventilation Rate. If the size of the basic Ventilation Rate and the user-influenced Ventilation Rate in the investigated dwellings are compared, it can be seen that 87% of the total air change Rate is caused by the behavior of the occupants.
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the effects of human behavior on natural Ventilation Rate and indoor air environment in summer a field study in southern japan
Energy and Buildings, 1997Co-Authors: Go Iwashita, Hiroshi AkasakaAbstract:Abstract Residents completed a questionnaire survey assessing indoor environment and residents' behavior (i.e. when they opened windows/doors, when they opeRated air conditioners, and so on) during the period of Ventilation measurement. The purpose of this study is to measure the Ventilation Rate in occupied dwellings in Kagoshima City, located in the southern part of Japan, using the tracer gas method and to investigate the relationship between the occupants' behavior in each dwelling and the energy consumption for air conditioning during the summer period. Based on the continuous measurement of the Ventilation Rate in eight dwellings, the proportion between the total Ventilation Rate (Ventilation Rate during occupancy of the dwellings) and the basic Ventilation Rate (Ventilation Rate during non-occupancy and with door/windows closed) is discussed. The measuring principle applied is the constant concentration tracer gas method. The main conclusion is that there is a large difference between the mean basic Ventilation Rate and the mean total Ventilation Rate. If the size of the basic Ventilation Rate and the user-influenced Ventilation Rate in the investigated dwellings are compared, it can be seen that 87% of the total air change Rate is caused by the behavior of the occupants.
James K. Russell - One of the best experts on this subject based on the ideXlab platform.
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the impact of Ventilation Rate on end tidal carbon dioxide level during manual cardiopulmonary resuscitation
Resuscitation, 2020Co-Authors: Sofia Ruiz De Gauna, James K. Russell, J J Gutierrez, Jesus Ruiz, Mikel Leturiondo, Izaskun Azcarate, Digna M Gonzalezotero, Carlos Corcuera, Mohamud DayaAbstract:Abstract Aim Ventilation Rate is a confounding factor for interpretation of end-tidal carbon dioxide (ETCO2) during cardiopulmonary resuscitation (CPR). The aim of our study was to model the effect of Ventilation Rate on ETCO2 during manual CPR in adult out-of-hospital cardiac arrest (OHCA). Methods We conducted a retrospective analysis of OHCA monitor-defibrillator files with concurrent capnogram, compression depth, transthoracic impedance and ECG. We annotated pairs of capnogram segments presenting differences in average Ventilation Rate and average ETCO2 value but with other influencing factors (e.g. compression Rate and depth) presenting similar values within the pair. ETCO2 variation as a function of Ventilation Rate was adjusted through curve fitting using non-linear least squares as a measure of goodness of fit. Results A total of 141 pairs of segments from 102 patients were annotated. Each pair provided a single data point for curve fitting. The best goodness of fit yielded a coefficient of determination R2 of 0.93. Our model described that ETCO2 decays exponentially with increasing Ventilation Rate. The model showed no differences attributable to the airway type (endotracheal tube or supraglottic King-LT-D). Conclusion Capnogram interpretation during CPR is challenging since many factors influence ETCO2. For adequate interpretation, we need to know the effect of each factor on ETCO2. Our model allows quantifying the effect of Ventilation Rate on ETCO2 variation. Our findings could contribute to better interpretation of ETCO2 during CPR.
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abstract 436 Ventilation Rate impact on end tidal carbon dioxide levels during manual cardiopulmonary resuscitation
Circulation, 2019Co-Authors: Jesus Ruiz, James K. Russell, Sofia Ruiz De Gauna, J J Gutierrez, Mikel Leturiondo, Carlos Corcuera, L A Leturiondo, Mohamud DayaAbstract:Introduction: End-tidal carbon dioxide (ETCO2) levels during cardiopulmonary resuscitation (CPR) depend primarily on the blood flow geneRated by chest compressions, on the Ventilation Rate and on t...
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Feasibility of the capnogram to monitor Ventilation Rate during cardiopulmonary resuscitation.
Resuscitation, 2016Co-Authors: Elisabete Aramendi, Andoni Elola, Erik Alonso, Unai Irusta, Mohamud Daya, James K. Russell, Pia Hubner, Fritz SterzAbstract:Abstract Aim The Rates of chest compressions (CCs) and Ventilations are both important metrics to monitor the quality of cardiopulmonary resuscitation (CPR). Capnography permits monitoring Ventilation, but the CCs provided during CPR corrupt the capnogram and compromise the accuracy of automatic Ventilation detectors. The aim of this study was to evaluate the feasibility of an automatic algorithm based on the capnogram to detect Ventilations and provide feedback on Ventilation Rate during CPR, specifically addressing intervals where CCs are delivered. Methods The dataset used to develop and test the algorithm contained in-hospital and out-of-hospital cardiac arrest episodes. The method relies on adaptive thresholding to detect Ventilations in the first derivative of the capnogram. The performance of the detector was reported in terms of sensitivity (SE) and Positive Predictive Value (PPV). The overall performance was reported in terms of the Rate error and errors in the hyperVentilation alarms. Results were given sepaRately for the intervals with CCs. Results A total of 83 episodes were considered, resulting in 4880min and 46,740 Ventilations (8741 during CCs). The method showed an overall SE/PPV above 99% and 97% respectively, even in intervals with CCs. The error for the Ventilation Rate was below 1.8min −1 in any group, and >99% of the Ventilation alarms were correctly detected. Conclusion A method to provide accuRate feedback on Ventilation Rate using only the capnogram is proposed. Its accuracy was proven even in intervals where canpography signal was severely corrupted by CCs. This algorithm could be integRated into monitor/defibrillators to provide reliable feedback on Ventilation Rate during CPR.
