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  • Yakima Software
    the Hamilton Ontario accident a couple of years ago It was not discovered at that time and the cause was attributed to intermittent interlock failure The subsequent recall of the multiple microswitch logic network did not really solve the problem The second Yakima accident was again attributed to a type of race condition in the software this one allowed the device to be activated in an error setting a failure of a software interlock The Tyler accidents were related to problems in the data entry routines that allowed the code to proceed to Set Up Test before the full prescription had been entered and acted upon The Yakima accident involves problems encountered later in the logic after the treatment monitor Treat reaches Set Up Test The Therac 25 s field light feature permits very precise positioning of the patient for treatment The operator can control the Therac 25 right at the treatment site using a small hand control offering certain limited functions for patient setup including setting gantry collimator and table motions Normally the operator enters all the prescription data at the console outside the treatment room before the final setup of all machine parameters is completed in the treatment room This gives rise to an unverified condition at the console The operator then completes the patient setup in the treatment room and all relevant parameters now verify The console displays the message Press set button while the turntable is in the field light position The operator now presses the set button on the hand control or types set at the console That should set the collimator to the proper position for treatment Figure 4 Yakima software flaw In the software after the prescription is entered and verified by the Datent routine the control variable Tphase is changed so that the Set Up Test routine is entered see Figure 4 Every pass through the Set Up Test routine increments the upper collimator position check a shared variable called Class3 If Class3 is nonzero there is an inconsistency and treatment should not proceed A zero value for Class3 indicates that the relevant parameters are consistent with treatment and the beam is not inhibited After setting the Class 3 variable Set Up Test next checks for any malfunctions in the system by checking another shared variable set by a routine that actually handles the interlock checking called F mal to see if it has a nonzero value A nonzero value in F mal indicates that the machine is not ready for treatment and the Set Up Test subroutine is rescheduled When F mal is zero indicating that everything is ready for treatment the Set Up Test subroutine sets the Tphase variable equal to 2 which results in next scheduling the Set Up Done subroutine and the treatment is allowed to continue The actual interlock checking is performed by a concurrent Housekeeper task Hkeper The upper collimator position check is performed by a subroutine of Hkeper called Lmtchk analog digital limit checking Lmtchk

    Original URL path: http://computingcases.org/case_materials/therac/supporting_docs/levenson/Yakima%20Software%20Problem.html (2016-04-30)
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  • Procude Malfunction 54
    Cancer Center physicist after he discovered how to reproduce the Malfunction 54 error Enter the room and set up the machine for an electron beam treatment by selecting a field size and installing the trimmers Press the set button Leave the room and close the door At the control console proceed to the patient set up display For Mode enter X The machine will default to 25 MeV and go to dose rate of 250 rads min Use return key to go to dose Enter 200 Use return key to go to time Enter 0 8 min Use the return key to rapidly advance to the bottom of the display Immediately use the up arrow to move from the bottom of the display You are now in the edit mode Use the up arrow to go to the top of the display and change the mode X to E for electrons Change the energy from 25 to 10 Use the return key to go back down to the bottom of the display Wait for the beam ready message then type B return The unit will have no indications on dose rate or dose 1 or dose 2 for about 3

    Original URL path: http://computingcases.org/case_materials/therac/supporting_docs/therac_resources/produce_malfuction_54.html (2016-04-30)
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  • Operator Inteview
    is sometimes a deciding factor when people make the decision on how much training Int Yeah that shocks me Op It s really frustrating But I can t say that with AECL I was I was not on board when they first got that machine because you only get it when you first get the machine and then from that point on every year after if you get a new employee you are doing the hands on training so you re passing it on Int Did they give any did AECL give any books or documentation Op I would assume they would ve just because I know what was going on back then but I just wasn t part of the recipient to that because I was on board 7 years after they got that machine so I was getting it from the staff as a student and as an operator then Now we do that with our Siemans equipment I know what we had here on board and yes they do leave several binders that show you how to operate the machine as well as five days of on site training by an application specialist And I believe they have about 5 for the Siemans company and I think the other major company manufacturing LAs is Varian I don t know if you ve heard of them So right now Varian and Siemans are pretty much the biggies Then there s the Phillips company which got bought out by Electa is probably like number 3 and Mitsubishi is still selling LA as well out of Japan so I think those are like the 4 that I can think of right now today that are as big as AECL back in 1985 when this happened They were probably number 3 back then There was Varian Siemans probably AECL Right now its still Varian and Siemans kind of neck and neck Anyways they all have about the same number of application specialists depending on how many accelerators they sell that year So that if they sell twice as many all of a sudden then they ll beef up their application specialists and get those people ready to go out in the field then and train all of us So it s usually you know average of 4 to 5 days You barter when you buy a LA for the training time if it s gonna be over and above that or sometimes we ve had pieces of equipment not LA but if we re gonna have more than two people get trained you have to go to their site to train Then you have to pay for it yourself so a lot of the bartering goes on depending upon if they come to your site or if you go to their site and who pays for it And I think it s kind of hokey hokey stuff in my opinion But we have to pay 7000 to get our person trained just because we got a computer over here but the training site is out there and it s something we re bartering for so let s say Oh we don t want software upgrades for free We re gonna take training instead These are like bargaining tools that the companies use You know if I could change anything I d love to change that I think that s ridiculous But you know we re stuck Our hands are tied These companies with all the money you know Our hands are tied We have to do you know we look at what our needs and if we think trainings more important we ll pay for it so it depends on the institution Int But it could be possible for a clinic especially in MN where the operators don t have to be certified to have uncertified operators and then cutting costs on training Op Could be could be Now LA what this accident occurred on are much better than some of the other pieces of equipment that deliver radiation treatments There s other things that um high dose rate units there s planning computers that aren t really delivering the radiation but they re gonna drive the LA later Those are the ones where these companies are sticklers on this training stuff being a bartering tool and costing money Ultimately we re on this era right now that you won t even be able to fathom what s going on in this field I don t say that you know to knock you cause you don t have the knowledge Int No I understand Op I just mean I can t even fathom it myself what s going on But we re at this era in radiation therapy that some people are considering is comparable to when CT came out in radiology You remember how big that was Or when MRI came out And so we re in this process where we re doing some planning on these computers because of 3 dimensional software now So this issue s gonna be huge and we won t be able to laughs I don t know how we re ever gonna track what we were doing then let alone back when this accident happened how difficult it was to figure out what went wrong So with 3 d software everything was 2 d back then we were treating from front and back and left and right and real simple parallel pulse fields we called it With this 3 d software and I keep pointing to that thing cause that s what s gonna do it that s the stuff where all the people have to go to get training and pay 7000 to get it That s gonna be driving the LA eventually and we ve already got the link for our new accelerator set up So through cyber space it downloads all this information 3 dimensionally and the way they re why they re relating it to what CT was is because now we can instead of just giving radiation straight out of the machine all the dose throughout the whole square field is even from left to right edge and top to bottom and front to back Now you can actually insert little devices that are driven by this computer to the LA that will make it like we re painting with radiation so we ve got spots of this square now that are gonna get a higher amount maybe in the middle or maybe less over here cause there s a lens of an eye and less over here cause the spinal cord is in the way We can do that now with this 3 d software running the linear accelerators So this issue is going to come up again It s gonna scare the heck outa me and the FDA that approves the software to run these accelerators I hope to God is doing their job really well that s all I can say you know because I ll never know Again we re all going to be trusting that these companies that sell the software to run the machines three dimensionally now and do all this fancy stuff like CT we re gonna trust that the FDA caught all the bugs in the software or the company s working with the FDA then And it s way more complex than back in those days when this incident occurred and that was a software bug Basically it was a software bug Int It was two actually two software bugs but one of the big problems back in those days was that while companies were required to report to the FDA clinics were not So AECL even though I think they were possibly at fault in a number of ways with that didn t even know about some of the accidents because until much later because they were never told Op Sure That s true too You got both things going on you know So I think we re better today than then as far as reporting so these alerts come out the one component Int Are clinics required now to report Op Oh yes Yeah Any kind of thing that you find that you think is a funny fluke in the software I hope everybody you know that they re I mean you know even though you re required there s gonna be people that are still gonna choose not to do it cause the paper trail that you have to deal with when you submit something like that But hopefully there s enough reputable radiation ecology in the field that those things are important to protect the public and we don t want any of that bad ink that happened in the 85 I think we re all pretty good about that but I mean I got this tiny little network of people that when you go to a national conference that s all you re basing this on is that you think people are genuinely honest and yes they are going to take the time and know that they re going to have a huge month s worth of paper trail because they they ve submitted something like that you know Int And they submit to the FDA or to Op I think like we Siemans would be us if we found a little bug that we re suspicious something funny s going on However there s other ways to report like if you have an error that you found made Whether it s an error that s from the equipment that would go one way to Siemans and then they d report But if we made an error a technical error on somebody s treatment we re responsible to report And again it s only it s gonna be as good as the system will only be as good as the honesty of the people reporting so that s something But you can go to there s a governmental report that comes out every quarter where you can read the errors that occurred in radiation therapy centers So if somebody you know made an error or somebody discovered an error whether it was intentional or not So let s say I was supposed to treat your right breast and I treated your left breast and that happened about two years ago where somebody went through a whole course of radiation therapy the wrong breast for example down in Florida That should be reported to the government and then the government publishes that report for the public So I know that is out there for that mechanism The software or hardware bugs that we may find or suspect we ll report to Siemans someone ll come out and test something and then Siemans will report it That s where I don t know who they report it to I m sure it s a government agency but I don t know if it s the FDA Int AECL They worked with both FDA and Canada s equivalent of the FDA Op Ok But what about like the nuclear regulation commission in the United States Do they have a similar agency up there Cause I would think that s part of the loop you know the FDA here doesn t really control radiation the NRC does Int And what about the Center for Devices and Radiological Health Op That s that would be another one Int And but they re part of FDA Op That I don t know either but I often see things coming from them So that would be I Int I think they re part of FCA Op you know what I think that s where Siemans would report S Op yep Int I think they re FCA Op I think that s so if Siemans suspected it A software bug or something like what happened here Int ok Op And so they The only thing I can say is I don t see us talking about that very often You know I think when you buy a LA and maybe your applications person is coming doing your training to your staff that would be a good thing that they should teach and I ve never heard that I know it cause I know how the system works Int like how it works Op Yeah And we teach our students that cause I ve been in this long enough or whatever The physicists have been around for twenty years so they re real good about saying If you notice something funny make sure you tell me But I would think the companies that sell you the accelerators would promote that more and they don t You know So I think that would be something we could improve upon as a community working with accelerators I don t remember one application specialist ever teaching that that I can think of And I think that would be something the company would really want to do to cover their butts you know Int You would think Op You d think they d just have a form saying here if you ever notice anything funny fill this out fax it to us You know what I mean Cause you could just do something real quickly Or you they could have a website where you could go and report all that Int And they don t Op Maybe I just don t know about it because they have maybe they have it but they haven t taught us about it you know what I mean And I would think that would be just a real quick easy way I mean you wouldn t want to tell them every little thing but you should have a system in your department where if you suspect something as a therapist I d bring it to my physicist or whomever would be in charge and have them test it without a patient in the room and then if they think it s really a bug they should just be able to get on the website for Siemans and tell them they ve discovered this You know something really quick And I just don t know if they re if that exists and they re not telling us That s what I mean the education component I think we re lacking on You know I think there could be way more promotion with those that are getting new machines and getting training that the applications people should be promoting that kind of thing Constantly saying if you get this fault and you know whatever challenging em and making em think about it cause they re covering their equipment then you know Anyways that s my high horse on that one laughs Int Ok Well when the test the operator from Texas is it operator or therapist what s the best Op Well it s radiation therapist today Couple years ago it was radiation therapy technologist and operator s fine too I think the lay person would understand operator much easier Cause people think of the therapist sometimes as the physician And they re actually called radiation oncologist that s the doctor s name So operator s just fine but if you re gonna speak to someone by title you usually say radiation therapist Int Ok Well the operator from Texas testified in one of the cases that she was told during training that she could never hurt anyone with Therac 25 That it was impossible That there were too many safety interlocks for that to happen So I m wondering if during your training on the Therac 4 did anyone ever tell you you know this Op I ve heard similar comments like that Int Really Op But I don t think I ve heard em since this incident to tell you the truth and we actually I think we teach just the opposite Int Now so that s changed Op Yeah I mean I think the whole issue of you know we all trusted what was going on was safe back then and yet there were so many detection systems but when things became computerized a lot of that just went out the door in my opinion When it was the manual for example when I used to run a Cobalt machine as a student and then finally as a therapist I think maybe in that case I would ve even felt more comfortable with someone telling me that or teaching me that Cause I knew that if the source didn t go back in the machine I could see that by a manual system and I could go in and get the patient out of the room But even then the patient would ve gotten overdosed if the source didn t go back in the lead safe let s say I don t know how much you know about Cobalt machines but the point was that it s a more simple machine and it was a manual system where if this rod stuck out or this light didn t go off So I wouldn t I couldn t even I wouldn t even need to rely on the light getting burnt out There was a rod The only thing that could ve gone wrong was again the rod might have malfunctioned and so that you know even then there I knew and I was taught that even that that would be the one last thing that could fail us right So as machines have gotten more and more complex I don t know if we can say that anymore however I know we tried to tell patients this that ask cause patients do ask Patients are getting more and more knowledgeable with what s going on out there because of the internet I think That s just changed everything and how we educate people It might be also that the baby boomers are coming up to now the point getting cancer and I think they were a type of generation that sought out information more Whereas the generation that in the past had been getting cancer was I don t know what was before they used to call em the World War II what was the what do they label that generation They re more the type Int Tom Brokaw says the greatest generation and I ve heard that more now Op Right They didn t seek out the information as much If their doctor recommended radiation therapy they didn t question it they just did it Well that generation is kinda moving through now and baby boomers are coming in so they are challenging the information So patients ask that and when we tell them Well the machine goes through 94 checks before it delivers a treatment and we ve got three categories of faults that we as a therapist can see on the screen Now I don t tell a patient that but I know when it s sending out the signal to test the treatment before it ll run and it ll come back to me before I even turn the machine on So that part you re feeling good about about the computer but yet you know that can still fail And so I don t think people are teaching therapists anymore not to just believe the computers and believe the equipment like they used to And it might just be because more and more of these accidents and little safety alerts are coming out now that we re hearing about Because the equipment s getting more and more complex It s just unbelievable Int Yeah Op It s scary you know So I don t remember ever getting taught that way where I was But I tend you know I ll just I think in MN we re I know where we all train and just you know the history of radiation therapy community in MN almost everybody got their training at the U of M doctors physicists and therapists Now it s branched out much more so in the last 5 to 10 years but all of us having had our training there I can actually even tell you about a individual that I would say has had the philosophy that has influenced all of us to have this kind of questioning philosophy and the patient comes first type of philosophy which is you know of course but where we just won t train people by saying you accept this as it is It s black or white We didn t have that training philosophy at the U of M So this doctor I want to talk about is Doctor Seymour Lovit who is kind of considered like the one of the grandfathers of radiation therapy and so so many of us coming out of that training program now branching out and starting our own training programs Hopefully we ve upheld that kind of philosophy where at least in MN it s really something I think I can speak to But I don t know what goes on in the rest of the country you know I m in my own little world here in MN but I at least know the network amongst ourselves I still think that s that philosophy s been upheld where we question it We don t teach a student that you should just think your machine is safe Because we know that s been proven otherwise Int Back at the time that these accidents occurred with Therac 25 the machines the messages that came back to the operator didn t make sense It would say something like Malfunction 54 or some other type of malfunction or just some numbers or a word So there wasn t really a lot given to the operator from the computer as far as what might be going wrong and also the company didn t provide any kind of simple key or a translation and I m wondering if that was your experience with the Therac machine you worked on and whether you think that might whether Siemans is doing a better job right now Op I know Siemans is doing a better job When I use that machine Int The Therac Op nod when I was fresh out of school I know there were some keys but they were really really basic back in those days you know I mean there s 94 faults now And I have a grid that I can look at and then they re categorized so I can kinda have an idea what s going on and make a judgement ok I m not gonna keep pushing this button to keep overriding this you know Int So you can still override Op You can still override Some things not all There s even mechanisms where a physicist can come and go into a different mode called service and go through this it s a diagnostic system where he can see or she can see what the faults were and why how often they occurred and when where everything was as far as the parameters of the equipment when it happened to see if it s linked to you know maybe the machine being down at 90 degrees instead of zero the weight of something is pressing on a wire you know even that kind of stuff Back then I can t tell you how much was available to me as an operator I know there were some things you know right above the machine that would cover the stuff I could grab a training manual but you know now we ve got 4 binders and pages of the stuff because it s gotten more complex I know there were still things that would occur that would not be answered or addressed by the binders and I have still had that even now I ve been operating a machine where it quits on me in the middle of a treatment doesn t tell me why and usually it s you know I was told when I was trained it ll always give me a reason A fault will be at the bottom 94 things that are all categorized by software hardware and LA faults ok I ve still run the machine where no fault has come up and it stops on me and I don t know why And that drives me crazy That makes me think there s still software bugs out there happening Int So what s the procedure now Op when that happens Int for Siemans I guess you d contact them Op I report it to our physicists they ll try to duplicate it they ll report it even if they can t duplicate it Our service engineer or a Siemans service engineer will come and try to duplicate it They ll eventually tell us back have they been able to or not and what they ve done about it They can t duplicate some of that stuff So you don t know if it s a power surge because somebody turned on an air conditioner in the Piper building that caused it cause they can t duplicate it Or not So some of it there s still some you know loodoodoodoo stuff that goes on out there in cyberspace that we can t answer Int Was it different back in the 80s Op The process where I was on that Therac 4 was very similar If we d get a fault we couldn t explain we d call someone We were very fortunate we had physics staff right on site service engineers right on site And could call in and have a corporate service engineer that was in an hour Now so I felt good about Int Corporate AECL Op Yep We could ve if we needed to Depending on their district and how many service guys they d have per state let s say Siemens we could get a guy in an hour and a half Varium it might have taken a day to get somebody from California so it depends on the equipment You have a different service contract with each company and they even spell out how quickly they can respond how much they ll charge you all that kind of stuff But some places choose to have in house people trained on the equipment because that can be a savings a cost saving and it can be more convenient to have somebody there quickly So we have both and most places will do that They ll have one guy trained on some of the basics but they ll go out again you pay for it but they ll go out to the Siemans corporate headquarters in Palo Alto California have a five week training course on LA operation and repair And so they can do some of the basics Anything they get stuck on they ll call in the Siemans gentleman So it s very similar even back then I can just say that the books and binders and things that I d go to when I had a fault weren t as well written let s say Int Back then mh hm Op And we were trained more much more thoroughly I think I ve trained much more thoroughly on that because I went through the applications training on these new machines But the people that were training me on the job that were the therapists that were my colleagues didn t do as much of that as I think we do nowadays They just said here s how you run it They didn t really go over the inner workings of when malfunctions would occur as much We re really focused on the patient care aspect the technical component of accurately delivering treatment And we tend as therapists to leave the on the job training stuff about the machine to the physics staff and the service engineers and that just wasn t a component of my training on the machine It was a component of my training in the classroom So there s some part of us that knows that you ve gotten some of that in the classroom but yet you re responsible to teach em the idiosyncrasies of that machine or that company s machine when you re on the job learning with someone So I didn t get a lot of that no Int Ok Did AECL charge It sounds like Siemans charges to have someone come and look at something Op I don t know back then what they charged if they did charge Most of the service contracts are set up where you have a one year warranty anything s for free After that you choose Do you want to continue a service contract for 140 000 a year and I m sure it s more than that now I would guess it s probably up to who knows 180 000 a year Or you can get a minimal contract and then overtime is more Which everybody has overtime cause you re running a machine from 7 30 to 4 30 The only time service guys can come in are when you re done with your patients to work on things if it at least functions to get you through the day And again you have to make the decision where if it s sluggish and you re running poorly and you re you know pressing the button seven times to get one course of treatment Int The override Op Exactly We make the decision we don t want to continue that and we down it But it could still sluggishly limp along if you choose that So anyways there s different contracts available different prices different companies switch tape sides Op 8am if we when we re warming it up the machine and testing it at 7am before we start treating patients he may not get here until 9 so we have to make the decision Down the machine and treat everybody on one machine and then we tag team and try to quickly get our patients in so they re not waiting forever and we still stay on schedule Int Do you feel like the administration at the hospital has the same goal as far as patient treating as the treatment staff or as the therapy staff does Op I do Here at this institution I don t know how others would answer that but part of my job kinda being the middle person too is making sure that I educate them on what is happening so the squeaky wheel gets the oil you know If we re having major machine problems and it s just getting ridiculous then I can tell them how many patients have complained and I really try to bring that forth on the staff complaints for that matter too They don t feel it s safe or whatever So I can bring that to our administrator or manager and relate it to the cost issue You know it s usually going to boil down to cost Do we want to spend the money to have the overtime for the service engineer to get this thing fixed so we don t lose patients Cause in the long run we ll have a cost issue that way We ll lose revenue Because patients won t come here cause we ll lose their trust So I really see that as my role trying to get that into some kind of concrete form that administration can buy is tough I ve gotta show how many patients this has affected what kind of money that would bring in and have it icky you know I have that icky feeling it all relates to money But yet the experience and the reputation and all that is the part that I really can sell you know I ve gotta get the numbers for em but I don t even like that part I can sell the patient concerns I can get Dr Kim to get on the phone and call my manager and say You know this is really bad We ve had this we ve had patients come from other institutions telling us the same thing so we know what it s like Somebody ll come here and say I think they made an error on me Can you look through my records I don t want to have any more treatments over there Can I come here I mean this just happened two weeks ago So this goes on out there So that part is a easy sell to administration then if you have that kind of thing going on But you know you have to I don t just say it unless it happens too I have to have some facts And so if I do my job well yes they ll buy in And I don t think I very often have too hard a sell But I know other managers have a hard sell on this issue I can tell you what s caused some of this is the balanced budget act in 1997 that went through is killing all of us in health care right now And so Medicare which 65 of the patients in this department are Medicare and how they choose to reimburse us is really the thing that s killing a lot of hospitals when these issues come up You have these decisions to make that indirectly the government s controlling It s just that s a whole nother path we can go down a whole nother topic that it s huge Int So there is pressure to keep patients going through and you know so would you Op Yeah It s just sad that it comes down to the financial stuff sometimes I think we here are lucky that we re financially maybe one of the more stable hospitals so that decisions can be made based on safety and not you re financial dollar signs don t even enter in And I don t think we d ever compromise anything If it did come down to a dollar sign you know the patient safety would come first and the legal issues Of course any institution knows in the long run you can shoot yourself in the foot if you didn t listen to these things But I know that some managers have a real hard time with this and I networking with colleagues I hear this Int At other hospitals Op Yeah It s just horrible I think the private clinics or the free standing clinics have less of an issue with this with money but yet they re the ones that may be putting so many patients through kind of on assembly line kind of system that depends on the physicians running the group in that case are they I hate to say it but you know are they greedy for the money or not is gonna be the issue Now in an institution like this one Int And this is more publicly funded is that right or what s the difference Op Well we re non profit a non profit organization which can help and hurt you I mean you know so It s just a tough issue you know we re gonna be more affected by the governmental issues than in that case cause reimbursement s gonna be different than if we stay in the clinic So all those issues relate to this issue in that sense and if it boils down to the money versus you know somebody making a

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  • Summary of Interview
    happens all the time in medical radiation therapy particularly in clinics where there is more pressure from the administration to keep patients moving through quickly Although Susan had been working with a AECL Therac machine at the time of the accidents she did not remember receiving warning notices from AECL about the Therac related accidents Susan believes that this is one aspect of the industry that has changed possibly in part due the Therac 25 accidents At the present time Susan receives notices from the manufacturers of the linear accelerators used at her hospital whenever there is a linear accelerator malfunction or even if there is a malfunction that almost occurred but was prevented Perhaps part of the reason that Susan did not hear of the Therac 25 incidents until much later was that the hospital where she worked got rid of the Therac 4 moved their facilities and bought a new set of linear accelerators Susan estimated the average life of the linear accelerator to be between 5 and 10 years After that she said the accelerator tends to act somewhat like an old car in which the engine light is coming on all the time The accelerator s computer generates many faults that can become a nuisance to the operators and to the patients Responsible operators will continue to report these faults to the physicist when one is available and eventually the machine is replaced Susan feels that one of the biggest problems in her industry today is the lack of rigorous industry wide standard certification and education for operators Susan reported that there are about 102 radiation schools in the country and that there are also different types of schools Students are able to receive a certificate from a certificate program usually about 12 months in length Students are also able to receive a four year bachelor s degree from certain schools The American Registry of Radiologic Technologists ARRT provides a test that graduates of these programs may then take in order to be considered licensed entry level technicians The ARRT also requires that therapists maintain their training through continuing education Therapists must have 24 credits in two years before they may re register their licenses In spite of the fact that the ARRT provides these guidelines for licensure many states in the U S do not require hospitals or clinics to hire licensed radiation therapists Some states require very basic exams but according to Susan that in essence means that in many states anyone off the street could learn how to operate a machine take one of these basic exams and then be qualified to operate radiation therapy machines Susan and many of her colleagues continue to fight for mandatory standard certification of radiation therapists The safety of patients depends on all of the elements of their systems of treatment working together correctly The more operators are trained to know about the process the more they will be able to help prevent accidents Well trained operators

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  • References
    Human Error Cambridge Cambridge University Press 1990 Reason is an expert on human machine interactions His book contains excellent analyses of system safety and many detailed studies of system accidents with references His analysis of how systems should be built to take advantage of human abilities rather that to emphasize their shortcoming is well worth the price of the book 5 C Perrow Normal Accidents Living with High Risk Technologies Princeton NJ Princeton University Press 1984 A classic text in system safety Perrow s argument is that technological systems are becoming so complex to build and maintain that catastrophic accidents will become normal 6 C W Huff Unintentional power in the design of computing systems In T W Bynam S Rogerson Eds Computer ethics and professional responsibility p 98 106 London Basil Blackwell 2004 p 98 106 An analysis of the often undesired power that software engineers hold over those who use systems they design The article uses Therac 25 as an example 7 C W Huff R Brown Integrating ethics into a computing curriculum A case study of the Therac 25 In A Akera W Aspray Eds Using history to teach computer science and related disciplines Washington DC Computing Research Association 2004 pp 255 277 pdf available An analysis of the Therac 25 case that tries to set the race condition erros in the context of the computing knowledge of the time It concludes that so little was known about race conditions in software at the time that responsibility for them is unclear Still there are many other ways AECL could have avoided the problems even in the presence of race conditions Additional Therac Sources C A Bowsher Medical Devices The Public Health at Risk US Gov t General Accounting Office Report GAO T PEMD 90 2 046987 139922

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  • Machado Table of Contents
    California Irvine Header and Text of Email Machado Sent Office of Academic Computing Office of Academic Computing Action Office of Academic Computing Students Responses Machado and his Email Some Background

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  • Legal Climate
    violent reaction such as stalking acts of bigotry threats of violence or other hostile or intimidating fighting words Such words include those terms widely recognized to victimize or stigmatize individuals on the basis of race ethnicity religion sex sexual orientation disability and other protected characteristics Masking or falsifying one s identity in an email is also listed as a violation of the policy and is prohibited The OAC did not have a specific procedure to follow for each case of computer misuse that might arise It did have an informal agreement worked out with the Dean of Students The Dean of Students stance was that once students had been admitted to the college they have access like any other student to the various services on campus If rules regarding use of those services are violated they can be revoked The OAC deals directly with any such cases without contacting the Dean until it is an issue that is beyond the scope of the computer use policy In most cases once a problem is identified the OAC contacts the person gets their attention by locking their access to their email account and holds an internal hearing for the student with a few faculty and staff Federal law At the time of this incident 1996 there were no California laws regarding email use Under federal law any threats of force that had the intention of interfering with specifically protected activities e g voting access to public education was illegal This law was called the Federally Protected Activities Act of 1968 Enacted in response to violent attacks on civil rights workers in the South the act does the following Prohibits intentional interference by force or threat of force with certain specified constitutional rights including voting and election activities participation in programs administered or

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  • University of California at Irvine
    the top 50 universities overall Election to the American Association of Universities AAU a group of 60 of the most distinguished research institutions is another indication of UCI s stature in the academic community UCI is a young university founded in 1964 with its first graduating class in 1968 It has nevertheless achieved distinction as an excellent public university Admissions standards are competitive with the average high school GPA being 3 7 and median SAT scores verbal math about 1100 Orange County Orange County California is part of the metro area that makes up the greater Los Angeles area It is on the southern edge of Los Angeles and is host to the University of California Irvine It is a multi ethic society and citizens expect that dealing with race relations will be with them for some time The following figures are taken from the 1996 Orange County Annual Survey done by the Department of Urban and Regional Planning at the University of California Irvine Most people felt the economy was in good shape and that jobs were easy to find Crime and immigration were rated as the top two problems people felt needed attention 52 of whites reporting voting 4 or more times over the last four years while only 15 of Hispanics and 6 of Asians reported this much political involvement Race and College Representation in California Orange County and UCI Over the past decade minority races have become the majority in California This is true for Orange County and the University of California Irvine as well The table below shows the percentages of the total population that are accounted for by each of several racial groups using categories from the 1990 census report Note that though the percentage of Hispanics in the population has been increasing rapidly

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