Reliability and Fault Tolerance Essay Example | Topics and Well Written Essays - 2500 words

Reliability and Fault Tolerance - Essay fountReport also indicates that s perpetuallyal patients suffered serious injuries during the accident. In fact, the Therac-25 accident has been described as the worst ever series of beam of light accidents in more than three decades of accelerator medical history (Leveson 1995, p. 18). This paper seeks to sit a detailed analysis of the Therac-25 radiation over paneling accident in light of technologies and equipments involved, what caused the accident and its consequences. The strain will also explore measures that ought to have been taken to prevent the accident. The Therac-25 radiation overdose accident of mingled with June 1985 and January 1987 has been described as the worst ever radiation accident in the history of medical accelerators. The accidents resulted from the radiation overdose caused by the Therac-25 therapy simple machine. Report indicates that at least six patients were overdosed in a span of most 2 years due to faults of the machine. Report indicates that the radiation overdose was several times the normal therapeutical dose resulting in severe burns and death, in some cases (Leveson 1995, p. 18). The first complaint of an accident was describe on June 3, 1985, when a female patient was placed on a 10-MeV electron treatment to collarbone area. However, few minutes later on turning on of the Therac-25 machine, the patient complained of extreme force of heat on the body. It is then that the patient complained of having been burned by the machine. ... Nevertheless, the company still failed to investigate whether Therac-25 burned the patients or not. briefly afterwards, the patient developed reddening and swelling at the area treated by the machine. The pain increased to a level that shoulder began freezing as spasms continued to appear. The patients condition continued to worsen, all the way indicating that the patient had suffered from radiation (Nancy and Clark 1993, p.19). A second series o f the accident occurred at Ontario Cancer Foundation in 1985 just a week after the first patient had been overdosed at Kennestone. Report indicates that the Therac-25 at the Hamilton clinic had been in use for about six months (Leveson, Turner and Sarin 1993). However, on July 26, 1985, a patient aged 40 years old visited the hospital for the treatment of carcinoma of the cervix. Leveson, Turner, and Sarin (1993) indicate that the Therac-25 machine shut down exactly five minutes after activation. This time around, the machine indicated an H-tilt error message. It also displayed a no dose and treatment pause (Nancy and Clark 1993, p.19). Despite these warnings, the operator went ahead to press the proceed button expecting the Therac-25 machine to shift the right does this time around. Despite this being, a normal procedure since the machine had shown such faults before the machine still failed to operate. The procedure was repeated several time, but the machine showed suspend. The operator continued with the treatment after which the patient began complaining of a burning sensation on the treatment area, which she described as an electric tingling shock (Leveson, Turner and Sarin 1993). Other patients were successfully treated that day without accidents. The