The Therac 25 Disaster October 2012 1 Introduction The Therac-25 was a machine for cancer treatment manufactured by the Atomic Energy of Canada Limited (AECL) and went down to history as one of the world’s worst software disasters. The machine was released to the market in 1983 and was later involved in at least 6 accidents that lead to enormous radiation overdoses for the patients. One of the major innovations of the Therac-25 was the move to complete computer control‚ which allowed operators
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The Therac 25 A case study in safety failure • Radiation therapy machine • “The most serious computer-related accidents to date” • People were killed • Reference: Nancy Leveson and Clark Turner‚ “The Investigation of the Therac-25 Accidents”‚ Computer‚ 26‚ 7 (July 1993) pp 18-41. Therac 25 Background • Medical linear accelerator developed by Atomic Energy of Canada‚ Ltd. in mid-1970s • Delivers 25 MeV photons or electrons of various energies • Controlled by PDP-11 minicomputer • Software
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An Investigation of the Therac-25 Accidents -- Part III Nancy Leveson‚ University of Washington Clark S. Turner‚ University of California‚ Irvine Reprinted with permission‚ IEEE Computer‚ Vol. 26‚ No. 7‚ July 1993‚ pp. 18-41. Recall that the Tyler error occurred when the operator made an entry indicating the mode/energy‚ went to the command line‚ then moved the cursor up to change the mode/energy‚ and returned to the command line all within 8 seconds. Since the magnet setting takes about 8 seconds
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as they launched their new cancer therapy machine‚ Therac-25.The machine according to the chief engineer offered two modes of radiation therapy to cure cancer. This machine according to some was the innovation of the century and a gift to mankind. As the team of engineers was celebrating the day of the launch of their “successful invention”‚ the medical team of the Death Valley Cancer Hospital (DVCH) was installing the first ever model of Therac-25.This was not the only big news why AECL was in the
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SAC PRESIDENT’S LETTER 25 by 25 is not 625 We‚ doctors‚ nurses‚ cardiology technicians and other professions related with cardiology have hopes and projects for our personal‚ institutional and society lives. Yet‚ we sometimes feel confused when we think about the population. What can we do to improve public health? We can all contribute and work together with our Society. During the past year‚ we have launched the 25 by 25 Program. 25 by 25 is the project of the Argentine Society of Cardiology and
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In Journal 25‚ where I will discover course improvements I need to make or already have made to correct my results and experience. A. Describe an important course correction you have made in the past. I was a 17 years old senior in high school. Not taking university application seriously. True that I graduate high school with high grade point average. However‚ I missed the university application deadline. I’ve should have known that everything has a deadline nothing going to wait. So I ended up
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Chapter 25 Primary Sources Louis Napoleon Bonaparte Campaign Statement 1. Louis Napoleon based his claim to rule France on the fact that he is so devoted to France and the Republic. 2. Louis Napoleon wanted to devote himself wholly to the preservation and consolidation of the Republic as president of France‚ but when he becomes the self-proclaimed emperor of France later‚ all his promises are void. His promises are revealed to be pieces of persuasion so he gets elected as president. Abraham
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Chapter 25 Notes Hard Facts: Manchuria: Japan takes over the providence of Manchuria‚ China‚ in 1931. Due to this the League of Nations began to fail. Shortly after Japan withdrew from the leave and took over the rest of China. Due to this the threat in Asia and the Pacific increased. This was the first event leading up to the war. Benito Mussolini: Italian Fascist who became dictator. He supported the World War and joined forces with Nazi Germany to for the Rome-Berlin Axis. Nazis: National
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Chapter 25 Having just learned about state constitutions and legislatures in the previous chapter‚ the following chapter is based on local government and finance. It is broken up into the following 4 sections: Counties‚ Towns‚ and Townships‚ Cities and Metropolitan Areas‚ Providing Vital Services‚ and Financing State and Local Government. First I will talk about Counties‚ Towns and Townships. Counties are a major unit of local government in most states‚ which is created by the State. There are
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candidates for business process management? I think the reason for both of the companies because they are large and everywhere. • AmerisourceBergen Because is one of the world’s largest pharmaceutical services companies and a member of the fortune 25‚ with 70 billion in revenue in 2009. It provides drug distribution and related services designed to reduce cost and improve patient outcomes‚ servicing both pharmaceutical manufactures and healthcare providers. AmerisourceBergen is so large has numerous
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