scholarly journals Low-Cost Differential Pressure Spirometry for Emergency Ventilator Tidal Volume Sensing

Author(s):  
Jordan Edmunds ◽  
Mauricio J Bustamante ◽  
Samuel J Raymond ◽  
David B Camarillo ◽  
David K Piech ◽  
...  

COVID-19 has become a significant burden on the healthcare systems in the United States and around the world, with many patients requiring invasive mechanical ventilation (IMV) to survive. Close monitoring of patients is critical, with total volume per breath (tidal volume) being one of the most important data points. However, ventilators are complex and expensive devices, typically in the range of tens of thousands of US dollars, and are challenging to manufacture, typically requiring months. Solutions which could augment the ventilator supply rapidly and at low cost in the United States and elsewhere would be valuable. In this paper, we present a standalone tidal volume measurement system consisting of a D-Lite spirometer, pressure sensor, microcontroller, and tubing with a cost of parts less than $50 USD. We also provide a model to predict the error in tidal volume measurements based on the pressure sensor used and the flow during ventilation. We validate this system and show that the tidal volume accuracy for flows above 10L/min was within 10%. We envision this system being used to increase the ventilator supply in resource-constrained settings.

Author(s):  
J. D. Oracheski ◽  
Neil Rausch

Enbridge Inc. operates the world’s longest crude oil and products pipeline system. The company owns and operates Enbridge Pipelines Inc. (the Canadian portion of the Enbridge crude oil mainline) and a variety of affiliated pipelines in Canada and the United States, including Enbridge Energy Partners, L.P. that operates the Lakehead Pipeline System in the United States. Much of the main pipeline system has been in operation for over 55 years. The mainline system has been in operation for over 55 years. The mainline system is comprised of approximately 15,000 kilometers (9000 miles) of pipeline, 3 million barrels of cavern storage and 3.7 million barrels of tankage (352 tanks) which collectively are integral to transporting more than 2.2 million barrels per day of crude oil and refined products. Enbridge’s measurement needs and practices have continuously evolved, with radar gauging on tanks becoming the standard over the past few years. This paper discusses a number of issues associated with the accuracy of volume measurements in upright, cylindrical petroleum product storage tanks with floating roofs. It includes the analysis and discussion of the process of determining tank volumes and the overall accuracy of a tank volume measurement system. It also includes a discussion of the influence and relevance of each measurement variable on the overall accuracy of tank volume measurements, in order to provide pipeline operators with some insight into determining which variables are most important to the process of tank volume measurement. Finally, it discusses issues regarding tank volume measurement system accuracy, as opposed to overall tank volume measurement accuracy. The focus of this paper is not on the uncertainty analysis process itself, but rather on understanding the results of the uncertainty analysis performed for tank volume measurement systems.


2017 ◽  
Vol 114 (26) ◽  
pp. E5021-E5023 ◽  
Author(s):  
Mark Z. Jacobson ◽  
Mark A. Delucchi ◽  
Mary A. Cameron ◽  
Bethany A. Frew

Author(s):  
Ken R. Tefertiller

Agriculture is one of the Nation’s most efficient industries. The cost of living for the average consumer would be considerably higher today without the low cost of food supplied by United States agriculture. This is particularly significant at a time when we hear so much about poverty in the United States and in other countries. Had it not been for the extremely low costs of food, there would be many more poverty stricken families today. Paper published with permission.


2021 ◽  
Vol 23 (1) ◽  
pp. 1
Author(s):  
Sigit S. Nugroho

Assessing the output of past foreign policy is instrumental for any country to learn policy-relevant insights, to appreciate its experience, and to improve its future conduct. To glean such insights, this article borrows Baldwin’s framework in assessing the success and failure in foreign policy. Using a case study analysis, it assesses the United States’ (U.S.) influence attempt towards Indonesia to resolve the 1999 East Timor humanitarian crisis. President Clinton’s decision to undergo an influence attempt primarily aimed to change Indonesia’s policy while gaining support from U.S. allies in the process. The article finds that Clinton’s decision was a highly successful attempt. This finding is based on several factors: (1) the attempt effectively attained the intended primary and secondary goals at a considerably high degree; (2) it was conducted at a considerably low cost for the U.S.; (3) it inflicted a high cost towards Indonesia; (4) the increase in Clinton’s stake strengthened the U.S. resolve to pursue the influence attempt; and (5) Clinton had successfully overcome the difficult undertaking as Indonesia possessed higher stake over East Timor. These findings provide some lessons for both U.S. and Indonesian foreign policymakers to chart future relations for the two nations.


2018 ◽  
pp. 666-670
Author(s):  
Olha Bohomolets

The article studies the history and the current stage of Russia’s aggression to-wards countries with lower military potential. The collapse of the post-war system of international relations and collective security has become apparent: the aggression of Russia against Moldova, Georgia and Ukraine has testified to the fact that there are no longer any tools to protect countries subjected to discrimination from super powers. Today discrimination affects not only people or social groups, but also some countries. Such countries are not capable of pursuing an independent policy as to major centres of international power they have to deal with. Peculiar to these countries are uncompetitive economy, low quality of life and undeveloped civil society, they hence become a target for “vital interests”, namely bidding by so-called super powers. “Giants” are attracted by the geographical location of a possible “victim”, access to the sea, transit facilities, natural resources, especially energy, low-cost labour, etc. It is often that “discriminated” countries become grounds for ignition of burning or frozen conflicts provoked by powerful neighbours’ influence, or are exposed to open aggression and become subject to occupation or hybrid war. This has all started after the Second World War, when super powers of the USSR and China, on the one hand, and the United States, Great Britain, Australia, and others, on the other, have made Korea fall into two states. In addition, there was subsequently a division of Germany, the Caribbean crisis…However, such conflicts then were not that wide-ranging, since the post-war collective security system was quite effective. Things, though, have changed dramatically in recent decades. One of the largest global players − Russia – has decisively begun to create around itself a buffer zone formed of countries, where it fuels frozen conflicts and in such a way keeps them under the radar and hinders their integration into the Western world. Initially, Russia ignited a conflict in Nagorno-Karabakh, supporting Armenia and assisting it to invade a considerable part of the territory in Azerbaijan, and then initiated the war in Transnistria by virtually occupying part of Moldova’s territory and asserting itself there on the pretext of deploying a peacekeeping mission. Later, there was a war in Abkhazia and then − in South Ossetia aiming to detach part of Georgia’s territory. And lastly, the turn of Ukraine has come… Regrettably, Ukraine is a typical and another example of a country that has fallen victim of multifaceted interests of the leading global players − Russia, the United States and the EU, and has faced all possible forms of discrimination. Keywords: war in eastern Ukraine, military aggression, geopolitics, conflicts, buffer zones.


Author(s):  
Joseph T. Glatthaar

Since the 1970s, the United States has struggled to accept that its economic and military powers are finite. The Conclusion looks at ways the American military might make progress while acknowledging these limitations. The American military could be reinvigorated by better communication between politicians and military leaders, a return to traditional values of prudence and circumspection, and greater support during wartime. Technology may have transformed warfare, but enemies often find low-cost means of reducing their impact. The United States possesses the world’s most sophisticated military force, but sometimes the task is greater than it can fulfill, or the results are not worth the price.


2019 ◽  
Vol 43 (3-4) ◽  
pp. 152-188
Author(s):  
Onur Altindag ◽  
Theodore J. Joyce ◽  
Julie A. Reeder

Between July 2005 and July 2007, the Oregon Supplemental Nutrition Program for Women, Infants and Children program conducted the largest randomized field experiment (RFE) ever in the United States to assess the effectiveness of a low-cost peer counseling intervention to promote exclusive breastfeeding. We undertook a within-study comparison of the intervention using unique administrative data between July 2005 and July 2010. We found no difference between experimental and nonexperimental estimates but failed to determine correspondence based on more stringent criteria. We show that tests for nonconsent bias in the benchmark RFE might provide an important signal as to confounding in the nonexperimental estimates.


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