Therac-25 system is a radiation therapy machine that is used for cancer treatment. “The machine was quite advanced because the computer software made the system far easier to use. Basically, the operator only needed to enter the prescription on a computer terminal and the machine did the required adjustments automatically, reducing the setup time” (Wwwwolf, 2003, para.1).
The computer of the system is controlled by an operator. But, the computer has its sensors and information by which it can find out the errors and inform the operator. “The sensors in the machine reported on, among other things, the placement of the turntable and the strength and shape of the beam” (What therac-25 software did: Real-time software, n.d., para.10).
There are various levels of computer control. Therac-25 selects a system of control in which the computer proposes an action, and if asked by the operator, this action is implemented. The sensors and information help in providing error messages. The computer asks the operator if an action is to be performed to resolve the error that occurred. If the operator gives the command to do this action, the computer will implement the action. Under various conditions, the system implements different levels of control. There occurs a condition when the system produces an error message and the computer allows the operator to repeat the action by pressing a key. In this case, the computer proposes action and if the operator wants that action to be done, the computer will implement it. This is better than a condition in which the system is suspended if any error occurs and will continue its function only if the entire data is inputted again. In such a condition, the operator will have to do everything. Another condition is that the machine checks the system on its own with the help of the data inputted and does the actions accordingly. In this case, all functions are done by the computer by the action data given by the operator. This condition is better than a condition where the operator has to verify all the settings of the system. In such a condition, the operator has to do everything.
The level of computer control implemented in the Therac-25 system is suitable for the maximum efficient operation of the device because it performs the function without causing any injurious and poisonous harm to the human body. This machine provides safety and ease for the operators to perform the treatment inefficient manner as it is controlled by the computer system. With the usage of earlier radiotherapy machines, many cancer patients die during the treatment due to the overdosage of radiation from the machine. This happens because there is no safety system to control the machine. In the earlier radiotherapy machine, radiation spreads all over the air when it generates and it enters the non-cancerous tissues of the human body. Moreover, the high beam of radiation causes burn over the treated part and most probably the wounded patient dies due to the poison of radiation. The patients do not get cured well because the electric beam needed to destroy the cancerous tissues does not reach fully and deeply into the cancerous tissue.
Computer control is implemented in a therac-25 system to get a more efficient operation of the system. This machine is kept in a secured room and treatment is done and controlled by the operator from outside the treatment room. There are several hardware and software mechanisms in therac-25 systems which make the safety of the machine certain. These mechanisms help operate the machine inefficiently manner without any risk. The safety operation of the machine is mainly controlled by therac-25 software. The entire management of the function of the machine is done by the software which also detects the problem in the machine and reports instantly. It directs the machine to produce the beam of the electron at a safe level and prevents the generation of overdosage and low dosage of radiation. The computer system informs the operator of the appropriate action to be performed in the patient because the treatment to be given to the different patients is different. The patients may require a high dosage of radiation or a low dosage of radiation to destroy the cancerous tissue. So, this computer system informs the correct amount of electric beam to be applied to the patient. Thus, this computer-controlled therac-25 system helps the patients from dangerous injury by the overdosage of radiation. “Therac-25’s computerization made this laborious process much easier for operators, and allowed them to spend minimal time in setting up the equipment” (Thera-25 for treating cancer: Therac-25: a computer-controlled medical linear accelerator for treating cancer, n.d., para.5). The therac-25 machine does all the operations without any human involvement and not much time is needed to set the machine for performing the treatment.
Therac-25 is a complicated machine. The errors in the machine have caused several accidents. Accidents were mainly due to a huge amount of radiation. These high radiations were caused due to errors in programming, lack of proper interaction between the operator and computer, etc. The errors in the codes of programs can cause problems in the system. The system should be well designed for the avoidance of errors. Software plays an important role in the design of the system. Thus, to avoid errors in the system, the software should be well implemented.
References
Thera-25 for treating cancer: Therac-25: a computer-controlled medical linear accelerator for treating cancer. (n.d.). Computing case.Org. 2010. Web.
What therac-25 software did: Real time software. (n.d.). Computing case.Org. 2010. Web.
Wwwwolf. (2003). Therac-25. Everything2. Web.