Thanks so much for watching! If you would like to see another video involving a radiation therapy accident, please check out: th-cam.com/video/kHpLDBNgpFg/w-d-xo.htmlsi=exyumW1rfQSFGSjm
Sharing another incident, not well known, which didn't result in death or major trauma, but did result in the mistreatment of well over a hundred patients before it was caught, was at a center in the western US. In this case it was human error by the medical physicist, in how he performed his calibrations. The linacs dosimetry system is regularly calibrated by a medical physicist to an external standard, and that standard requires temperature and pressure corrections to obtain the correct measurement. The physicist did not have a properly calibrated pressure measurement unit available, so used the pressure reported at the local airport. The problem was, that the airport was at a considerably different altitude than the center where the machine was, so the machine's dosimetry system, the system most responsible for monitoring and delivering the correct amount of radiation per treatment, was mis-calibrated, and the issue wasn't caught until an external audit by an outside agency was performed. This is why, as in your industry, checks, and cross checks by different people and different instruments are performed to make sure that you have consistency, and accuracy. There are some jobs you don't screw up---what you work in, and what I work in, are two of those fields.
I really like how he breaks these complex disasters down, not oversimplifying them, but still taking away the parts that aren't important to the story. Like with his diagrams of a highly complex machine that just show a few wires and a fuse that are relevant to the problem. And he makes it cartoonishly clear that he is simplifying things so you don't imagine you understand what wasn't covered. I get frustrated with a lot of explanations that try to present a simple analogy as if it were the way things actually worked and the analogy immediately breaks down the moment you try to think about it. The best example is Hawking radiation, which isn't virtual particles, despite so many science communicators that present that analogy as if it weren't an analogy. (If anyone does want a real explanation look up Unruh radiation. It's a horizon effect.)
@@johnmclawson3982, Nope because if it was why is there not an equal number tunneling in and out. I watched the explanation In PBS space time but it's way high level for me
@@johnmclawson3982 As s33rlies4 mentioned, if it was that (much like the virtual particle analogy) an equal number would go in as would go out. Hawking radiation is a horizon effect. I would look up "Unruh radiation" or "Unruh effect" for a better explanation than I can give here, but any time you have a spacetime topology where spacetime curves away from you to a horizon from your perspective, the math for thermodynamic equilibrium works out to net positive energy coming from the horizon in your direction. Where spacetime curves towards you from your perspective, it works out to net negative energy. Until 2010, both Hawking radiation and the related Unruh effect were purely mathematical until a possible observation of Hawking radiation in 2010 (Franco Belgiorno at the University of Milan) and a possible observation of Unruh effect in 2019 (NA63 experiment at CERN) but both are still uncomfirmed.
i just watched that "Plainly Difficult" episode a few hours ago. Yes, I love his summations of things like that "No Worries, Mate!" This is not the first time where an electrical failure led to undesired effects. PG&E was installing an upgrade to the pressure regulators at a gas transmission pipeline site in Milpitas CA. When power was disconnected to the old regulators, they immediately went to allowing full pressure. A better designed system would have just kept the pressure regulators at the last position (fail safe). A few hours later, the San Bruno gas pipeline explosion & fire struck downstream on that pipeline.
Given that it's a LINAC, I wouldn't be surprised if it could be switched between x-rays and proton therapy. Kind of like the THERAC. Also, your mention of Challenger is interesting - the Shuttle Orbiter had four redundant flight control computers that would be polled for consensus. If one was found to be not agreeing with the others, its output would be discarded. So, somewhat similar to what you were discussing for nuclear plants. The SRBs, on the other hand, were an engineering nightmare. The field joints between each segment were horribly designed and used materials not rated for the temperatures they were trying to launch in. Most notably, each field joint did have two o-rings sealing it, but they were more or less directly in the path of any hot gases that might try to escape. And the material these o-rings were made of lost elasticity dramatically in cold weather. When the field joints flexed as the entire stack rocked after the main engines were lit, the o-rings were compressed but couldn't bounce back and seal the joint. Because they effectively were directly in the exhaust path, they started to erode. Combustion slag collecting in the gap could re-seal it, which had happened on several previous cold-weather flights. But Challenger rode through wind shear that they think jarred the slag loose. I think the worst part was that all the SRB engineers at both NASA and Morton-Thiokol were screaming at their bosses to let the weather warm up a bit before trying to launch. They got told in no uncertain terms that they could either shut up or be fired, because Reagan was planning on mentioning Christa McAuliffe in his State of The Union later in the day and thus they had to launch on schedule. Edit: There's probably a good video or two out there on Challenger that might be worth a view. Plainly Difficult did one, IIRC.
As I commented on PD's video itself, they basically "learned from the Therac Incident but then immediately took a page from _The Freddy Fazbear School of Fail'safe' Engineering"_ and made the default state dangerous (active signal required to maintain _halt_ state) rather than default-safe (active signal required to maintain _active_ state). At least the hospital's _reaction_ to it was "oj pierdolemy, take it out of service immediately" rather than "it's fine and anyone that says otherwise will be the next one inside the machine"...
many of these flaws would be kinda like a reactor design where it has the control rods going up through the bottom of the reactor held by coils, with a flaw that on partial/complete loss of power, control rods would pull out completely
Kyle Hill and Low Level Learning (software development) also covered a similar device (Therac-25). So have many other channels. I thought this was one of them. As it is in Poland and licensed from France, this is a different device.
Technically, if the fuse failed, the control unit shouldn't have power at all or it shouldve lost the reference voltage. In either cases, it's riddiculous that the power loss on control unit doesn't "mechanically" (well, electrically) shut the entire system down.
I think the power supply was only for the sensor circuit, not the control module. This is done if a sensor requires a different voltage to power it correctly, but there should have been a controller input to test all other power suppliers were operating correctly. The diode failure situation is much more worrisome. It means the controller was only programmed to respond to negative feedback, it was not set up to detect if there actually was any feedback. Presumably a broken wire or a failed sensor would have had the same bad result. That's a failure in logic, and I'd think those units should have been taken out of service until the controller was upgraded.
The worst thing about any type of accident is that no matter how well every conceivable fault was planned for, there will always be something that couldn't have been known until it happened. Whether that comes from material, process, or knowledge. Also, please notice i said ever type of accident, not every accident.
Every linac I have ever worked on, has a feedback check to ensure that the ion chamber voltage is present right at the plates, and if not, it inhibits the beam. The circuits are normally designed to be fail-safe, such that any break in the wiring or loss of signal causes the interlock to inhibit. This must have been a very old design, or an improperly built version of the licensed design. Interestingly, the Neptune 10 was a version of accelerator put out by CGR of France, which was later acquired by AECL, who used on of the CGR designs, the Therac 6, as the basis of the Therac 20, then the Therac 25 which you also covered. Are we seeing a theme here? I believe all these used a scanned beam method of spreading the beam over a region of interest. In medical imaging, Europeans tend to use the term radiographers, and that term was extended to radiation therapy when it came into vogue. In the US, in radiation therapy, the term used is radiation therapist.
Correction cancer rates have NOT declined HOWEVER mortality associated with certain cancers has decreased due to early detection/early treatment with more effective tx modalities. Yes radiography is an archaic term here in the us we call it radiology or just imaging. In veterinary medicine they commonly call what we call for people X-rays vets call them radiographs. A radiographer would be akin to an radiology tech - someone who performs the study and a radiologist is an MD who interprets the study and reports to the md overseeing the patient. Whether a pcp, or specialist. As for crowns I’ve only seen the UA in my ED wear one in the nurses lounge during Halloween. Non scrub attire is frowned upon
I recommend watching the TH-cam videos (or the Wikipedia article) on the Therac-25 machine. That one overexposed many people, with the manufacturer claiming it is not possible. A little bit like the Post Office scandal in the UK.
i know some older 3d printers have a flaw with their temperature regulation where if they don't receive correct data from the nozzle/bed temperature sensor, it would supply maximum power to the heater indefinitely. this could cause fires, because nozzles can get way hotter than what software limits actually limit them to. thankfully, modern 3d printer firmware (such as marlin and klipper) will automatically shut themselves down if they detect incorrect heating behavior.
The O-ring was the physical reason for why the space shuttle failed and broke up (strictly speaking it didn't explode so much as get ripped apart by anomalous aerodynamic forces it was never designed to encounter), but it was not the root cause of the Challenger disaster. The root cause were issues of normalising anomalies and groupthink. The vehicle was sending the engineers and their managers warning signs that there were issues that could endanger a mission almost since its first flight, but the response to those red flags was attempts to rationalise them or explain them away or just ignore them until the laws of physics glanced harshly in their direction and demanded to know what the hell they thought they were doing. For example, O-ring erosion was never supposed to happen, but management rationalised it away as "We have 2 O-rings per joint, therefore we have redundancy. They didn't have redundancy at all because redundancy would have been the vehicle being designed to continue to operate even with one failed O-ring. It was not designed with that in mind, so even though it could continue to operate with a failed O-ring, the O-ring failing meant that the system as a whole had failed to operate as designed. It's like a bridge where one girder fails but the bridge doesn't collapse. You don't just keep using the bridge, you close it until repairs can be affected, and also launch an investigation into why the girder failed. Eventually, they pushed their luck too far, both O-rings failed to seal, and the rest is history. The sad thing is that the real lessons never seemed to have been learned, as the same sort of complacency and normalisation of anomalies led to the loss of Columbia too, even though there were red flags being thrown up as early as STS-27, only the second mission after Challenger, where the vehicle's heat shield was severely damaged and the crew only made it back alive due to sheer good luck.
It should also be mentioned that the field joint design worked just fine in warmer weather. It wasn't designed for year-round operations and weather cold enough to reduce the elasticity of the o-rings enough to fail only happens for a very small window in Florida. So they still would've been able to maintain a fairly high launch cadence even if they had to pause until the weather warmed up. The politicians and NASA leadership (effectively the same thing at that point) weren't satisfied with that and thus pushed them to launch even when conditions were known to be unsafe.
Radiography is called something different today, and I'm America. Radiology Technologists, or "rad techs" for short. Its an associates degree program at the same community college i went to for EMT and paramedic school.
I was surprised when I heard Białystok, my home is 50km away, I was born there, I was attending school there usually when I hear about those kinds of events they rarely came form poland and never heard about one that was so close to me also for curious biały stok means white hillside, and there is river called Biała - white (adj)
Did not watch it yet but my guess is therac 23. As we learned programming we had this as a reminder to be very careful with what we doing especially when programming low level stuff in school. (It was some kind of school that let you choose specialization). We also had the cases of this mars rover that crashed etc. Pretty tragic
I highly recommend this video by Cody'sLab where he extracted the potassium from bananas, he even measures the radioactivity of said potassium he extracts
The low severity score is technically correct, but it doesn't really capture the situation. Perhaps if a second egregiousness scale was also used where 0 indicates that the accident happened because of new science and 10 means a school kid would have known better. This accident would score fairly high on that scale. In contrast, the death of the Curies would be a 0 on the egregiousness scale since it was new science at the time.
He used to have two scales, a danger scale (how bad the incident was) and a _legacy_ scale (how much did the event change how things are done from now on). IIRC the Therac Incident was pretty high on the legacy scale, because it was like "whoops, maybe we DO need to keep hardware interlocks on this shit", and I'd put this one mid on the legacy scale because, while there was hardware interlocks, it _failed dangerous_ instead of failing safe.
I need one of these machines, but not the broken one in this particular story. I found out that I can't get head CTs anymore, because somehow the titanium in my neck messes up the image. That was how I was getting my annual extra radiation dose to kill off my weak cells, and ensure only the strong ones will continue dividing. Head CTs were the perfect route to go for two reasons: first, pretty much any good blow to the head was a guaranteed CT; and secondly, the Theory of Nuclear Reaganomics says that the radiation will trickle down through the rest of my body and make sure all my parts are adequately irradiated. Now I'll have to get someone to kick me in the tummy, and settle for an abdominal CT, and hope blood pressure will be enough to pump some of the radiation upwards. I could get a butt load of X-rays to my head instead, I guess, but that's going to get expensive fast. A particle accelerator would be perfect though. I could just give each major area its own smaller dose, and even out my strong cells way more effectively than trickling down does. My legs would really appreciate that.
This kinda reminded me of when we made steam sealing ineffective on purpose to make some serious steam leaks which ended up raising radioactivity in the Turbine Hall just to flex with our meters... showing people how irradiated we are. (I'm talking about a game and not real life, just saying we could land in Prison if we ever attempt something like that on such a level in a real power plant... or Graveyard due to fast moving Bullets) Does around 1100µSv cause a evacuation of the entire Power Plant?
I just have a question regarding Geiger counters and radioactive sources. I’ve heard according to the IAEA, you can’t measure two or more sources at once, only one at a time. Why is that, is it to protect the counter or for some other reason?
He talked about that in another video. If I remember correctly, what you heard about was probably NOT about multiple SOURCES BUT about more than one TYPE of radiation. A Geiger counter can‘t differentiate between alpha, beta and gamma radiation. It only measures the ionizing effect of that radiation, which leads to the measurement of all the mentioned types of radiation. I believe that the only factor limiting number of samples is the size of the samples compared to the area of the sensor ;-) Disclaimer: I am no expert and did not fact-check my memory m. I also don’t remember in which video(s) he mentioned that.
Who would of thought one of the most dangerous elements on the earth could be also the best Medication for the C Word or The means to destroy the world
Nobody deserves to have the power of the nuclear weapon But at the same time It's good that we have it It just needs to be more responsible Something above Russia and usa needs to be in control
This was a hardware inhibit, but set up in the wrong way. The default for various interlocks should be "shut down" and they should only by kept on by the power from the various control circuits and sensors. Similar to how home alarms work - closed circuit means it's OK, open circuit means problem, so if there is a wire break (say, someone cuts the wire), the alarm gets triggered. Instead, they did the opposite - a failed component meant that the alarm/interlock would never trigger.
@@Pentium100MHz the THERAC 25 use only Software interlock. This is why Change Energy from Proton to Electron generate this high Output. Filter wasn't in place before the beam goes on -> a Part of the Software doesnt Check Flags again and also Hardware interlock Like "Filter in place" doesnt exist on THERAC25. Also a variable overflow create a falls 0 = OK = beam on. My english is Bad, But THERAC25 is in the Radiotherapie a master Sample for complexity of interlock architecture in modern LINAC's.
@@NetrunnerAT Yes, but this video was not about that machine, but about a different one where failed hardware can result in beam on with more power than should be.
@@Pentium100MHz oh i See what you mean. I have address the issue "Software interlock" and "end User" the create this situation. My english is Basic. I Work with LINAC's by the way 😅 i think the Word Hardware failure isnt correct. Its realy a Software issue with No Hardware interlock present. Wiki discripe it very Well. Or i am Missing in Translation 🤣 See the Red haring.
@@NetrunnerAT That's cool. And yeah, AFAIK, with the Therac25 it was software written assuming there were hardware interlocks on a machine that did not have said hardware interlocks. The video was not about Therac25 though, it was about a different machine, with a different failure mode. Though I could probably say that I also use a linear particle accelerator at home, daily, though I'm sure it's much less powerful that what you work with. You can probably tell what it is.
The only reason cancer patients apparently live "longer" today is that they know sooner, but it's not really that they live longer. They just know longer. There are a few exceptions. Some forms of testicular cancer can be stopped dead in their tracks, even if they've gone Stage-IV. Non-Hodgkins lymphoma can also be cured (even when not caught early). Melanoma can be stopped, but only at its earliest stages.
@@Skyte100 Admittedly, I would probably opt for treatment because hope springs eternal, but my expectation of success would be quite low. Using my father as an anecdotal example, radiologists found a sweetpea sized tumor in one of his kidneys. The recommended procedure (though I thought total kidney removal was the most prudent) was to freeze the tumor (basically, the way you would do with a wart). This was 2014. The tumor disappeared completely after the "procedure." I didn't say anything to him, but my prediction was that, even after the cancer was seemingly gone, it would be back with a vengeance, and he'd be dead by 2020, and so he was. It first reappeared in and around the kidney. He was given surgery, and the cancer again seemed completely removed. I knew what the next phase would be: cancer in the lungs, which appeared about eighteen months later. After that, nothing could be done. So, he "survived" for more than five years (hooray for early diagnosis) -- five years from the time of discovery due to a chance MRI that had been conducted for a completely different issue. Had the cancer not been discovered until, say, 2018, then his life expectancy from the time of discovery would have been shorter, but his overall lifespan would have been the same. I am honestly FED UP with hearing about the "advancements" made to extend people's lives from the time of a cancer diagnosis. Like I said, what I see is earlier diagnoses, but outcomes generally remaining the same. Through the years, I've seen it with breast cancer, brain cancer, aggressive skin cancer, and leukemia. Sure, why not grasp at seedlings as you're sliding down a mountainside. Maybe you'll get lucky. Thus, I reiterate: Hope springs eternal.
![เจ้าผู้เดียว - ดิด คิตตี้ [OFFICIAL MV]](http://i.ytimg.com/vi/q0NLCYKBOTo/mqdefault.jpg)
Thanks so much for watching! If you would like to see another video involving a radiation therapy accident, please check out: th-cam.com/video/kHpLDBNgpFg/w-d-xo.htmlsi=exyumW1rfQSFGSjm
From the title, I thought this was going to be about Therac-25. It's almost like nothing was learned.
wait, it's not?
At least they did not ignore the skin irritation after multiple patients complained.
"I can tell this is going to end badly right away" - Yep, me too 🤣Another excellent video.Thanks for posting.
Glad you enjoyed it!
Plainly Difficult. Obviously it’s going to end poorly for someone, the question is just how many.
Sharing another incident, not well known, which didn't result in death or major trauma, but did result in the mistreatment of well over a hundred patients before it was caught, was at a center in the western US. In this case it was human error by the medical physicist, in how he performed his calibrations. The linacs dosimetry system is regularly calibrated by a medical physicist to an external standard, and that standard requires temperature and pressure corrections to obtain the correct measurement. The physicist did not have a properly calibrated pressure measurement unit available, so used the pressure reported at the local airport. The problem was, that the airport was at a considerably different altitude than the center where the machine was, so the machine's dosimetry system, the system most responsible for monitoring and delivering the correct amount of radiation per treatment, was mis-calibrated, and the issue wasn't caught until an external audit by an outside agency was performed. This is why, as in your industry, checks, and cross checks by different people and different instruments are performed to make sure that you have consistency, and accuracy. There are some jobs you don't screw up---what you work in, and what I work in, are two of those fields.
I really like how he breaks these complex disasters down, not oversimplifying them, but still taking away the parts that aren't important to the story. Like with his diagrams of a highly complex machine that just show a few wires and a fuse that are relevant to the problem. And he makes it cartoonishly clear that he is simplifying things so you don't imagine you understand what wasn't covered.
I get frustrated with a lot of explanations that try to present a simple analogy as if it were the way things actually worked and the analogy immediately breaks down the moment you try to think about it. The best example is Hawking radiation, which isn't virtual particles, despite so many science communicators that present that analogy as if it weren't an analogy. (If anyone does want a real explanation look up Unruh radiation. It's a horizon effect.)
@@johnmclawson3982, Nope because if it was why is there not an equal number tunneling in and out. I watched the explanation In PBS space time but it's way high level for me
@@s33rlies4The PBS Space Time video is great, but yeah, it takes watching it a few times to understand a lot of the harder subjects he covers.
@@johnmclawson3982 As s33rlies4 mentioned, if it was that (much like the virtual particle analogy) an equal number would go in as would go out. Hawking radiation is a horizon effect. I would look up "Unruh radiation" or "Unruh effect" for a better explanation than I can give here, but any time you have a spacetime topology where spacetime curves away from you to a horizon from your perspective, the math for thermodynamic equilibrium works out to net positive energy coming from the horizon in your direction. Where spacetime curves towards you from your perspective, it works out to net negative energy.
Until 2010, both Hawking radiation and the related Unruh effect were purely mathematical until a possible observation of Hawking radiation in 2010 (Franco Belgiorno at the University of Milan) and a possible observation of Unruh effect in 2019 (NA63 experiment at CERN) but both are still uncomfirmed.
He did a good job in explaining the Chernobyl disaster.
i just watched that "Plainly Difficult" episode a few hours ago. Yes, I love his summations of things like that "No Worries, Mate!"
This is not the first time where an electrical failure led to undesired effects. PG&E was installing an upgrade to the pressure regulators at a gas transmission pipeline site in Milpitas CA. When power was disconnected to the old regulators, they immediately went to allowing full pressure. A better designed system would have just kept the pressure regulators at the last position (fail safe). A few hours later, the San Bruno gas pipeline explosion & fire struck downstream on that pipeline.
Given that it's a LINAC, I wouldn't be surprised if it could be switched between x-rays and proton therapy. Kind of like the THERAC.
Also, your mention of Challenger is interesting - the Shuttle Orbiter had four redundant flight control computers that would be polled for consensus. If one was found to be not agreeing with the others, its output would be discarded. So, somewhat similar to what you were discussing for nuclear plants.
The SRBs, on the other hand, were an engineering nightmare. The field joints between each segment were horribly designed and used materials not rated for the temperatures they were trying to launch in. Most notably, each field joint did have two o-rings sealing it, but they were more or less directly in the path of any hot gases that might try to escape. And the material these o-rings were made of lost elasticity dramatically in cold weather. When the field joints flexed as the entire stack rocked after the main engines were lit, the o-rings were compressed but couldn't bounce back and seal the joint. Because they effectively were directly in the exhaust path, they started to erode. Combustion slag collecting in the gap could re-seal it, which had happened on several previous cold-weather flights. But Challenger rode through wind shear that they think jarred the slag loose.
I think the worst part was that all the SRB engineers at both NASA and Morton-Thiokol were screaming at their bosses to let the weather warm up a bit before trying to launch. They got told in no uncertain terms that they could either shut up or be fired, because Reagan was planning on mentioning Christa McAuliffe in his State of The Union later in the day and thus they had to launch on schedule.
Edit: There's probably a good video or two out there on Challenger that might be worth a view. Plainly Difficult did one, IIRC.
As I commented on PD's video itself, they basically "learned from the Therac Incident but then immediately took a page from _The Freddy Fazbear School of Fail'safe' Engineering"_ and made the default state dangerous (active signal required to maintain _halt_ state) rather than default-safe (active signal required to maintain _active_ state). At least the hospital's _reaction_ to it was "oj pierdolemy, take it out of service immediately" rather than "it's fine and anyone that says otherwise will be the next one inside the machine"...
I love plainly difficult cartoonish aproach to crazy incidents
many of these flaws would be kinda like a reactor design where it has the control rods going up through the bottom of the reactor held by coils, with a flaw that on partial/complete loss of power, control rods would pull out completely
John from Plainly Difficult has quite a few excellent videos on radiation incidents. Definitely worth looking at some of his other vids.
Almost to 77k subscribers!
Great videos keep up the good work
Thanks!!
Kyle Hill and Low Level Learning (software development) also covered a similar device (Therac-25). So have many other channels. I thought this was one of them. As it is in Poland and licensed from France, this is a different device.
Don't tell him that, he'll rob them next
Yeah, I initially thought it was going to be the Therac-25 thing as well.
Plainly Difficult has a video on that too.
Technically, if the fuse failed, the control unit shouldn't have power at all or it shouldve lost the reference voltage. In either cases, it's riddiculous that the power loss on control unit doesn't "mechanically" (well, electrically) shut the entire system down.
I think the power supply was only for the sensor circuit, not the control module. This is done if a sensor requires a different voltage to power it correctly, but there should have been a controller input to test all other power suppliers were operating correctly. The diode failure situation is much more worrisome. It means the controller was only programmed to respond to negative feedback, it was not set up to detect if there actually was any feedback. Presumably a broken wire or a failed sensor would have had the same bad result. That's a failure in logic, and I'd think those units should have been taken out of service until the controller was upgraded.
Lovely! Now im not only afraid of getting Cancer, but also treating it in Poland.
it's like how i do my assignments, no testing, it's a lucky day if it compiles on the 1st try :3
The worst thing about any type of accident is that no matter how well every conceivable fault was planned for, there will always be something that couldn't have been known until it happened. Whether that comes from material, process, or knowledge.
Also, please notice i said ever type of accident, not every accident.
Its possible to actually use scintillation detectors alongside these machines to give a real time image of the cancer
Ugh - this is mildly terrifying. Makes me want to OD on A, C, E, and Selenium...
The crown is just so we can distinguish
Every linac I have ever worked on, has a feedback check to ensure that the ion chamber voltage is present right at the plates, and if not, it inhibits the beam. The circuits are normally designed to be fail-safe, such that any break in the wiring or loss of signal causes the interlock to inhibit. This must have been a very old design, or an improperly built version of the licensed design. Interestingly, the Neptune 10 was a version of accelerator put out by CGR of France, which was later acquired by AECL, who used on of the CGR designs, the Therac 6, as the basis of the Therac 20, then the Therac 25 which you also covered. Are we seeing a theme here? I believe all these used a scanned beam method of spreading the beam over a region of interest. In medical imaging, Europeans tend to use the term radiographers, and that term was extended to radiation therapy when it came into vogue. In the US, in radiation therapy, the term used is radiation therapist.
patients respond better when they go home with some kind of treatment, even if it's just some vitamins while the doctors figure out what to do.
ur one of my favurate video i been watching u for 1 year keep making vids
Correction cancer rates have NOT declined HOWEVER mortality associated with certain cancers has decreased due to early detection/early treatment with more effective tx modalities.
Yes radiography is an archaic term here in the us we call it radiology or just imaging. In veterinary medicine they commonly call what we call for people X-rays vets call them radiographs. A radiographer would be akin to an radiology tech - someone who performs the study and a radiologist is an MD who interprets the study and reports to the md overseeing the patient. Whether a pcp, or specialist.
As for crowns I’ve only seen the UA in my ED wear one in the nurses lounge during Halloween. Non scrub attire is frowned upon
I recommend watching the TH-cam videos (or the Wikipedia article) on the Therac-25 machine. That one overexposed many people, with the manufacturer claiming it is not possible. A little bit like the Post Office scandal in the UK.
i know some older 3d printers have a flaw with their temperature regulation where if they don't receive correct data from the nozzle/bed temperature sensor, it would supply maximum power to the heater indefinitely. this could cause fires, because nozzles can get way hotter than what software limits actually limit them to. thankfully, modern 3d printer firmware (such as marlin and klipper) will automatically shut themselves down if they detect incorrect heating behavior.
T. Folse I think this would be an example of a single point of failure.
The O-ring was the physical reason for why the space shuttle failed and broke up (strictly speaking it didn't explode so much as get ripped apart by anomalous aerodynamic forces it was never designed to encounter), but it was not the root cause of the Challenger disaster.
The root cause were issues of normalising anomalies and groupthink. The vehicle was sending the engineers and their managers warning signs that there were issues that could endanger a mission almost since its first flight, but the response to those red flags was attempts to rationalise them or explain them away or just ignore them until the laws of physics glanced harshly in their direction and demanded to know what the hell they thought they were doing.
For example, O-ring erosion was never supposed to happen, but management rationalised it away as "We have 2 O-rings per joint, therefore we have redundancy. They didn't have redundancy at all because redundancy would have been the vehicle being designed to continue to operate even with one failed O-ring. It was not designed with that in mind, so even though it could continue to operate with a failed O-ring, the O-ring failing meant that the system as a whole had failed to operate as designed. It's like a bridge where one girder fails but the bridge doesn't collapse. You don't just keep using the bridge, you close it until repairs can be affected, and also launch an investigation into why the girder failed.
Eventually, they pushed their luck too far, both O-rings failed to seal, and the rest is history. The sad thing is that the real lessons never seemed to have been learned, as the same sort of complacency and normalisation of anomalies led to the loss of Columbia too, even though there were red flags being thrown up as early as STS-27, only the second mission after Challenger, where the vehicle's heat shield was severely damaged and the crew only made it back alive due to sheer good luck.
It should also be mentioned that the field joint design worked just fine in warmer weather. It wasn't designed for year-round operations and weather cold enough to reduce the elasticity of the o-rings enough to fail only happens for a very small window in Florida.
So they still would've been able to maintain a fairly high launch cadence even if they had to pause until the weather warmed up. The politicians and NASA leadership (effectively the same thing at that point) weren't satisfied with that and thus pushed them to launch even when conditions were known to be unsafe.
Radiography is called something different today, and I'm America. Radiology Technologists, or "rad techs" for short. Its an associates degree program at the same community college i went to for EMT and paramedic school.
In my language we say radiography when taking x-rays of the body
I was surprised when I heard Białystok, my home is 50km away, I was born there, I was attending school there
usually when I hear about those kinds of events they rarely came form poland and never heard about one that was so close to me
also for curious biały stok means white hillside, and there is river called Biała - white (adj)
Most Americans or at least New Yorkers, who hear the city, think of Bialy's (bread rolls named for the city).
Great reaction 👍
Did not watch it yet but my guess is therac 23.
As we learned programming we had this as a reminder to be very careful with what we doing especially when programming low level stuff in school. (It was some kind of school that let you choose specialization).
We also had the cases of this mars rover that crashed etc.
Pretty tragic
It was not what I thought. There was another case with a flaw in the software, this js what I thought ^^.
I highly recommend this video by Cody'sLab where he extracted the potassium from bananas, he even measures the radioactivity of said potassium he extracts
The low severity score is technically correct, but it doesn't really capture the situation. Perhaps if a second egregiousness scale was also used where 0 indicates that the accident happened because of new science and 10 means a school kid would have known better. This accident would score fairly high on that scale. In contrast, the death of the Curies would be a 0 on the egregiousness scale since it was new science at the time.
He used to have two scales, a danger scale (how bad the incident was) and a _legacy_ scale (how much did the event change how things are done from now on). IIRC the Therac Incident was pretty high on the legacy scale, because it was like "whoops, maybe we DO need to keep hardware interlocks on this shit", and I'd put this one mid on the legacy scale because, while there was hardware interlocks, it _failed dangerous_ instead of failing safe.
@@WackoMcGoose The old Plainly Difficult Legacy scale got maxed out for Chernobyl & Bhopal, for example.
I know it's not the right video to post, but there's a updated version of Nucleares that's worth checking out the changes they've made.
This reminds me of the Therac-20 incident
I need one of these machines, but not the broken one in this particular story.
I found out that I can't get head CTs anymore, because somehow the titanium in my neck messes up the image. That was how I was getting my annual extra radiation dose to kill off my weak cells, and ensure only the strong ones will continue dividing. Head CTs were the perfect route to go for two reasons: first, pretty much any good blow to the head was a guaranteed CT; and secondly, the Theory of Nuclear Reaganomics says that the radiation will trickle down through the rest of my body and make sure all my parts are adequately irradiated.
Now I'll have to get someone to kick me in the tummy, and settle for an abdominal CT, and hope blood pressure will be enough to pump some of the radiation upwards. I could get a butt load of X-rays to my head instead, I guess, but that's going to get expensive fast.
A particle accelerator would be perfect though. I could just give each major area its own smaller dose, and even out my strong cells way more effectively than trickling down does. My legs would really appreciate that.
Please say you are just trolling....
Had radio and chemo in 82 for Leukaemia.
Please do an episode with Decouple!
Another banger
Speaking of medial devices. Maybe a descent topic for a video could be cobalt 60 rods.
Does 37 times the dose mean the cancers dead for sure?
Speaking of medical equipment. A descent topic for a video could be about cobalt60 rods.
This kinda reminded me of when we made steam sealing ineffective on purpose to make some serious steam leaks which ended up raising radioactivity in the Turbine Hall just to flex with our meters... showing people how irradiated we are.
(I'm talking about a game and not real life, just saying we could land in Prison if we ever attempt something like that on such a level in a real power plant... or Graveyard due to fast moving Bullets)
Does around 1100µSv cause a evacuation of the entire Power Plant?
I just have a question regarding Geiger counters and radioactive sources. I’ve heard according to the IAEA, you can’t measure two or more sources at once, only one at a time. Why is that, is it to protect the counter or for some other reason?
He talked about that in another video.
If I remember correctly, what you heard about was probably NOT about multiple SOURCES BUT about more than one TYPE of radiation.
A Geiger counter can‘t differentiate between alpha, beta and gamma radiation. It only measures the ionizing effect of that radiation, which leads to the measurement of all the mentioned types of radiation.
I believe that the only factor limiting number of samples is the size of the samples compared to the area of the sensor ;-)
Disclaimer: I am no expert and did not fact-check my memory m. I also don’t remember in which video(s) he mentioned that.
37 times higher? Does Veritasium have an alibi for the date of the accident?
Białystok - wszystko jasne
Who would of thought one of the most dangerous elements on the earth could be also the best Medication for the C Word or The means to destroy the world
Nobody deserves to have the power of the nuclear weapon But at the same time It's good that we have it It just needs to be more responsible Something above Russia and usa needs to be in control
Amazing to me how little effort is put into keeping tabs on these sources.
In this case, there is no source. It uses an electron beam, so if the power is off there is no radiation.
@@dracobengali yeah. I thought this was a different video. I spoke too soon and didn't have a chance to edit after the video.
that is therac-25 and that is good video I'm from poland
i'm sorry i was wrong that is realy similar
@@user-gq6vm1vl2zreally similar, because Neptune 10 (original french machine) and Therac were designed by Thomson nuclear medicine subsidiary
Yes ... Software inhibits are bad. Next human operators do things nobody expact it.
This was a hardware inhibit, but set up in the wrong way. The default for various interlocks should be "shut down" and they should only by kept on by the power from the various control circuits and sensors.
Similar to how home alarms work - closed circuit means it's OK, open circuit means problem, so if there is a wire break (say, someone cuts the wire), the alarm gets triggered.
Instead, they did the opposite - a failed component meant that the alarm/interlock would never trigger.
@@Pentium100MHz the THERAC 25 use only Software interlock. This is why Change Energy from Proton to Electron generate this high Output. Filter wasn't in place before the beam goes on -> a Part of the Software doesnt Check Flags again and also Hardware interlock Like "Filter in place" doesnt exist on THERAC25. Also a variable overflow create a falls 0 = OK = beam on.
My english is Bad, But THERAC25 is in the Radiotherapie a master Sample for complexity of interlock architecture in modern LINAC's.
@@NetrunnerAT Yes, but this video was not about that machine, but about a different one where failed hardware can result in beam on with more power than should be.
@@Pentium100MHz oh i See what you mean. I have address the issue "Software interlock" and "end User" the create this situation. My english is Basic. I Work with LINAC's by the way 😅 i think the Word Hardware failure isnt correct. Its realy a Software issue with No Hardware interlock present. Wiki discripe it very Well. Or i am Missing in Translation 🤣 See the Red haring.
@@NetrunnerAT That's cool. And yeah, AFAIK, with the Therac25 it was software written assuming there were hardware interlocks on a machine that did not have said hardware interlocks. The video was not about Therac25 though, it was about a different machine, with a different failure mode.
Though I could probably say that I also use a linear particle accelerator at home, daily, though I'm sure it's much less powerful that what you work with. You can probably tell what it is.
The only reason cancer patients apparently live "longer" today is that they know sooner, but it's not really that they live longer. They just know longer. There are a few exceptions. Some forms of testicular cancer can be stopped dead in their tracks, even if they've gone Stage-IV. Non-Hodgkins lymphoma can also be cured (even when not caught early). Melanoma can be stopped, but only at its earliest stages.
By this logic outside the exceptions there is no point to treatment because you won't live longer with it than without it.
@@Skyte100 Admittedly, I would probably opt for treatment because hope springs eternal, but my expectation of success would be quite low. Using my father as an anecdotal example, radiologists found a sweetpea sized tumor in one of his kidneys. The recommended procedure (though I thought total kidney removal was the most prudent) was to freeze the tumor (basically, the way you would do with a wart). This was 2014. The tumor disappeared completely after the "procedure." I didn't say anything to him, but my prediction was that, even after the cancer was seemingly gone, it would be back with a vengeance, and he'd be dead by 2020, and so he was. It first reappeared in and around the kidney. He was given surgery, and the cancer again seemed completely removed. I knew what the next phase would be: cancer in the lungs, which appeared about eighteen months later. After that, nothing could be done. So, he "survived" for more than five years (hooray for early diagnosis) -- five years from the time of discovery due to a chance MRI that had been conducted for a completely different issue. Had the cancer not been discovered until, say, 2018, then his life expectancy from the time of discovery would have been shorter, but his overall lifespan would have been the same. I am honestly FED UP with hearing about the "advancements" made to extend people's lives from the time of a cancer diagnosis. Like I said, what I see is earlier diagnoses, but outcomes generally remaining the same. Through the years, I've seen it with breast cancer, brain cancer, aggressive skin cancer, and leukemia. Sure, why not grasp at seedlings as you're sliding down a mountainside. Maybe you'll get lucky. Thus, I reiterate: Hope springs eternal.