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Background Nasal High Flow (NHF) therapy delivers flows of heated humidified gases up to 60 LPM (litres per minute) via a nasal cannula. Particles of oral/nasal fluid released by patients undergoing NHF therapy may pose a cross-infection risk, which is a potential concern for treating COVID-19 patients. Methods Liquid particles within the exhaled breath of healthy participants were measured with two protocols: (1) high speed camera imaging and counting exhaled particles under high magnification (6 participants) and (2) measuring the deposition of a chemical marker (riboflavin-5-monophosphate) at a distance of 100 and 500 mm on filter papers through which air was drawn (10 participants). The filter papers were assayed with HPLC. Breathing conditions tested included quiet (resting) breathing and vigorous breathing (which here means nasal snorting, voluntary coughing and voluntary sneezing). Unsupported (natural) breathing and NHF at 30 and 60 LPM were compared. Results Imaging: During quiet breathing, no particles were recorded with unsupported breathing or 30 LPM NHF (detection limit for single particles 33 μm). Particles were detected from 2 of 6 participants at 60 LPM quiet breathing at approximately 10% of the rate caused by unsupported vigorous breathing. Unsupported vigorous breathing released the greatest numbers of particles. Vigorous breathing with NHF at 60 LPM, released half the number of particles compared to vigorous breathing without NHF. Chemical marker tests: No oral/nasal fluid was detected in quiet breathing without NHF (detection limit 0.28 μL/m3). In quiet breathing with NHF at 60 LPM, small quantities were detected in 4 out of 29 quiet breathing tests, not exceeding 17 μL/m3. Vigorous breathing released 200–1000 times more fluid than the quiet breathing with NHF. The quantities detected in vigorous breathing were similar whether using NHF or not. Conclusion During quiet breathing, 60 LPM NHF therapy may cause oral/nasal fluid to be released as particles, at levels of tens of μL per cubic metre of air. Vigorous breathing (snort, cough or sneeze) releases 200 to 1000 times more oral/nasal fluid than quiet breathing (p < 0.001 with both imaging and chemical marker methods). During vigorous breathing, 60 LPM NHF therapy caused no statistically significant difference in the quantity of oral/nasal fluid released compared to unsupported breathing. NHF use does not increase the risk of dispersing infectious aerosols above the risk of unsupported vigorous breathing. Standard infection prevention and control measures should apply when dealing with a patient who has an acute respiratory infection, independent of which, if any, respiratory support is being used. Clinical trial registration ACTRN12614000924651

Background Nasal High Flow (NHF) therapy delivers flows of heated humidified gases up to 60 LPM (litres per minute) via a nasal cannula. Particles of oral/nasal fluid released by patients undergoing NHF therapy may pose a cross-infection risk, which is a potential concern for treating COVID-19 patients. Methods Liquid particles within the exhaled breath of healthy participants were measured with two protocols: (1) high speed camera imaging and counting exhaled particles under high magnification (6 participants) and (2) measuring the deposition of a chemical marker (riboflavin-5-monophosphate) at a distance of 100 and 500 mm on filter papers through which air was drawn (10 participants). The filter papers were assayed with HPLC. Breathing conditions tested included quiet (resting) breathing and vigorous breathing (which here means nasal snorting, voluntary coughing and voluntary sneezing). Unsupported (natural) breathing and NHF at 30 and 60 LPM were compared. Results (1) Imaging: During quiet breathing, no particles were recorded with unsupported breathing or 30 LPM NHF (detection limit for single particles 33 microns). Particles were detected in 2 of 6 participants at 60 LPM quiet breathing at approximately 10% of the rate caused by unsupported vigorous breathing. Unsupported vigorous breathing released the greatest numbers of particles. Vigorous breathing with NHF at 60 LPM, released half the number of particles compared to vigorous breathing without NHF. (2) Chemical marker tests: No oral/nasal fluid was detected in quiet breathing without NHF (detection limit 0.28 microlitres/m3). In quiet breathing with NHF at 60 LPM, small quantities were detected in 4 out of 29 quiet breathing tests, not exceeding 17 microlitres/m3. Vigorous breathing released 200-1000 times more fluid than the quiet breathing with NHF. The quantities detected in vigorous breathing were similar whether using NHF or not. Conclusion During quiet breathing, 60 LPM NHF therapy may cause oral/nasal fluid to be released as particles, at levels of tens of microlitres per cubic metre of air. Vigorous breathing (snort, cough or sneeze) releases 200 to 1000 times more oral/nasal fluid than quiet breathing. During vigorous breathing, 60 LPM NHF therapy caused no statistically significant difference in the quantity of oral/nasal fluid released compares to unsupported breathing. NHF use does not increase the risk of dispersing infectious aerosols above the risk of unsupported vigorous breathing. Standard infection prevention and control measures should apply when dealing with a patient who has an acute respiratory infection, independent of which, if any, respiratory support is being used.

Treatment of vision-threating elevated intraocular pressure (IOP) for severe glaucoma may require implantation of a glaucoma drainage device (GDD) to shunt aqueous humor (AH) from the anterior chamber of the eye and lower IOP to acceptable levels between 8 and 21 mm Hg. Nonvalved GDDs (NVGDDs) cannot maintain IOP in that acceptable range during the early postoperative period and require intra-operative modifications for IOP control during the first 30 days after surgery. Other GDDs have valves to overcome this issue, but are less successful with maintaining long-term IOP. Our research goal is to improve NVGDD postoperative performance. Little rigorous research has been done to systematically analyze flow/pressure characteristics in NVGDDs. We describe an experimental system developed to assess the pressure drop for physiologic flow rates through NVGDD-like microtubes of various lengths/diameters, some with annular inserts. Experimental pressure measurements for flow through hollow microtubes are within predictive theory's limits. For instance, a 50.4 μm inner diameter microtube yields an average experimental pressure of 33.7 mm Hg, while theory predicts 31.0–64.2 mm Hg. An annular example, with 358.8 μm outside and 330.7 μm inside diameters, yields an experimental pressure of 9.6 mm Hg, within theoretical predictions of 4.2–19.2 mm Hg. These results are repeatable and consistent over 25 days, which fits the 20–35 day period needed for scar tissue formation to achieve long-term IOP control. This work introduces a novel method for controlling IOP and demonstrates an experiment to examine this over 25 days. Future efforts will study insert size and degradable inserts.

As part of a recent effort to develop an analytical verification test suite for building fabric models of whole building energy simulation programs, two new transient conduction analytical tests have been developed. These new tests make it possible to use boundary conditions that are typical of real building conduction heat transfer conditions. This paper describes the corresponding analytical models and the derivation of the solutions. Some details of existing tests are given for the sake of completeness. The zone description and parameter requirements necessary to apply the tests, along with results from two test programs, are also presented. Practical application: Building energy simulation programs are being increasingly relied upon by practicing engineers for design, performance evaluation and in demonstrating regulation compliance. Accordingly there is a significant demand for simulation model and computer program quality assurance. These tests can be used by developers and users to demonstrate a program’s ability to calculate conduction heat transfer processes.

The original use of the vehicle dashboard was to provide enough sensory information to inform the driver of the current engine and vehicle status and performance. Over time, it has evolved into an entertainment system that includes person-to-person communication, global positioning information, and the Internet, just to name a few. Each of these new features adds to the amount of information that drivers must absorb, leading to potential distraction and possible increases in the number and types of accidents. In order to provide an overview of these issues, this paper summarizes previous work on driver distraction and workload, demonstrating the importance of addressing those issues that compete for driver attention and action. In addition, a test platform vehicle is introduced which has the capability of assessing modified dashboards and consoles, as well as the ability to acquire relevant driving performance data. Future efforts with this test platform will be directed toward helping to resolve the critical tug-of-war between providing more information and entertainment while keeping drivers and their passengers safe. The long-term goal of this research is to evaluate the various technological innovations available for inclusion in the driving environment and determining how to optimize driver information delivery without excessive distraction and workload. The information presented herein is the first step in that effort of developing an adaptive distraction/workload management system that monitors performance metrics and provides selected feedback to drivers. The test platform (1973 VW Beetle converted to a plug-in series hybrid) can provide speed, location (GPS), 3-D acceleration, and rear proximity detection. The test drive route was a 2 km × 3 km city street circuit which took approximately 25 minutes to complete. Data is provided herein to demonstrate these capabilities. In addition, the platform has driver selectable layouts for the instrument cluster and console (LCD screens). The test platform is planned for use to determine driver preferences (e.g., dashboard/console configurations) and attention performance in addition to identifying optimal real-time feedback for drivers with different demographics.

Accommodations for disabilities in the workplace have improved significantly in recent years. Despite these improvements, an analysis [1] found that only “15.6% of workers with disabilities report needing accommodations, and 12.2% report receiving them.” Cottonwood Industries was founded in 1972 and is located in Lawrence, KS. A variety of jobs such as labeling, textiles, medical, and packaging are completed by employees. A large portion of the 140 person workforce at Cottonwood Industries is limited by physical and/or mental disabilities. Of these disabilities, 10 workers have full use of only one hand and struggle daily with simple tasks such as packaging. Manager, Steve Steinbach, identified a strong need for a device which would assist these workers by reducing frustration and speeding up the packaging process for them.Copyright © 2013 by ASME

Nasal high-flow therapy and dispersion of nasal aerosols in an experimental setting Sally Roberts, N. Kabaliuk, Cjt Spence, Jane O'Donnell, Z. Zulkhairi Abidin, R. Dougherty, S. Roberts, Y. Jiang, Mc Jermy University of Canterbury, New Zealand Fisher & Paykel Healthcare, New Zealand University of KS, USA Auckland District Health Board, New Zealand University of Auckland, New Zealand Background/Purpose: Nasal high-flow (NHF) therapy delivers flows of heated and humidified gases up to 60 L/min via a nasal cannula. NHF is widely used to support patients, including those who may be infectious. It is thought that NHF gas flow velocities may increase cross-infection risk. Methods: Aerosols within the exhaled breath of healthy volunteers were imaged. Experimental breathing conditions deemed as typical patient breathing conditions were tested: at rest, with a violent exhalation (snorting), both with and without NHF, at flows of 30 and 60 L/min, and for both separate nostrils. The number, diameter, evaporation rates, and velocity of exhaled aerosols were collected. Results: The numbers of aerosols measured were greatest during a violent exhalation without NHF and reduced with NHF. The numbers of aerosols were higher at 60 than 30 L/min, suggesting that higher gas flow rates may be associated with increased aerosol production; however, the numbers were on average 43% and 56% less than without NHF, respectively. During breathing at rest, no differences were imaged between with and without NHF, except at 60 L/min where numbers of aerosols produced were equivalent to 10% of a violent exhalation. Aerosol trajectory and evaporation rates observed both with and without NHF predicted that aerosols between 25 and 250 μm may travel up to 4.4 m and remain airborne for 43 seconds. Conclusions: NHF use does not increase the risk of dispersing infectious aerosols above the risk of typical patient breathing with violent exhalation, which is the worst-case clinical scenario; therefore, standard risk control measures should apply.

New heat transfer correlations were developed for two-phase heat transfer in a horizontal pipe for different flow patterns. Flow patterns were observed in a transparent circular pipe (2.54 cm I.D. and L/D = 96) using an air/water mixture. Visual identification of the flow patterns was supplemented with photographic data, and the results were plotted on the flow regime map proposed by Taitel and Dukler and agreed quite well with each other. A two-phase heat transfer experimental setup was built for this study and a total of 150 two-phase heat transfer data with different flow patterns were obtained under a uniform wall heat flux boundary condition. For these data, the superficial Reynolds number ranged from 640 to 35,500 for the liquid and from 540 to 21,200 for the gas. Our previously developed robust two-phase heat transfer correlation for a vertical with modified constants predicted the horizontal pipe air-water heat transfer experimental data with good accuracy. Overall the proposed correlations predicted the data with a mean deviation of 1.0% and an rms deviation of 12%.