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Post by sage on Jul 11, 2021 18:31:10 GMT
In the expanse we are told that medical procedures cannot be done under zero G.
The importance of gravity to medical procedures cannot be understated during long spaceflights or military engagements.
So the question I pose is what is the minimum acceleration needed to do medical procedures on a spaceship.
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Post by AtomHeartDragon on Jul 12, 2021 20:14:55 GMT
In the expanse we are told that medical procedures cannot be done under zero G. The importance of gravity to medical procedures cannot be understated during long spaceflights or military engagements. So the question I pose is what is the minimum acceleration needed to do medical procedures on a spaceship. You know that spin gravity is easy, right?
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Post by dragon on Jul 25, 2021 22:19:17 GMT
Depends on the size of the ship. Warships we have on CoADE are much too small to be any good for that. Small medical centrifuges could be used to spin up the patient (sedated, of course, it'd be way too nauseating otherwise), with a teleoperated surgical robot for performing procedures without spinning up the doctor to nauseating speeds (such a robot failing would make for nice a bit of drama, too, since the doctor would have then to operate in rather extreme conditions).
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Post by AtomHeartDragon on Jul 26, 2021 16:14:16 GMT
Depends on the size of the ship. Warships we have on CoADE are much too small to be any good for that. Small medical centrifuges could be used to spin up the patient (sedated, of course, it'd be way too nauseating otherwise), with a teleoperated surgical robot for performing procedures without spinning up the doctor to nauseating speeds (such a robot failing would make for nice a bit of drama, too, since the doctor would have then to operate in rather extreme conditions). You can tether a ship and a countermass (possibly propellant or supply store, transhab or another ship in nose-to-nose orientation) and spin that up. If the ship is has crew area sufficiently abaft of center mass you can also just tumble it. Given relatively weak propulsion technology and the penalty of encasing additional volume in armour, I would expect tumbling transhab-warship pairs to be the norm in the setting when in transit or stationing somewhere.
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Post by sage on Jul 30, 2021 1:47:25 GMT
Depends on the size of the ship. Warships we have on CoADE are much too small to be any good for that. Small medical centrifuges could be used to spin up the patient (sedated, of course, it'd be way too nauseating otherwise), with a teleoperated surgical robot for performing procedures without spinning up the doctor to nauseating speeds (such a robot failing would make for nice a bit of drama, too, since the doctor would have then to operate in rather extreme conditions). You can tether a ship and a countermass (possibly propellant or supply store, transhab or another ship in nose-to-nose orientation) and spin that up. If the ship is has crew area sufficiently abaft of center mass you can also just tumble it. Given relatively weak propulsion technology and the penalty of encasing additional volume in armour, I would expect tumbling transhab-warship pairs to be the norm in the setting when in transit or stationing somewhere. You missed the point of my question. I'm not asking about the method of gravity generation. What I'm asking about is the amount of gravity needed. What is the acceleration needed to do medical procedures? Is it 0.1 Earth Gravity, 0.5 or 1 Earth Gravity needed for medical procedures. Not whether the gravity is produced by counter mass, centrifuges or tumbling. The amount need by G force. Also as a side question the Q-force list in the game is Earth Gravity right? Just checking my units.
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Post by dragon on Jul 30, 2021 9:40:38 GMT
Nobody knows, since nobody has ever attempted a medical procedure in anything but 1G. Hence, your actual question has no known answer. In the future, there will likely exist 0G medical procedures. There might be some now, for the ISS, but I suspect they're strictly first aid, if anything serious would happen to one of the crew, he or she would be crammed into a Soyuz and sent back to Earth ASAP. If needed, the ISS crew can get back to Earth in less time than it'd take some people in rural areas to drive to a nearest doctor. The only long-duration flight without this option were the lunar missions, and the plan for these was to send up healthy, strong men and hope they manage to stay like this.
I suspect any gravity that you can feel is better than none at all. The more, the better, although in certain situations lower gravity might be medically useful, so on a centrifuge, the medbay would likely extend into low-G areas and have a way of moving the patient between levels. Where it's impossible to generate gravity for the whole ship, compact spin systems like I described might be used to generate localized gravity (of arbitrary strength) in order to enable normal procedures to be enacted.
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Post by airc777 on Aug 4, 2021 22:48:23 GMT
I think we would need to actually build a small scale O'niell cylinder to get proper data on the subject, or at least a semi permanent moon or mars base. Minimum viable gravity is something we would also need to know for long term health, not just medical procedures. If humans can survive low gravity for the very long term then we could build much larger slower turning O'niell cylinders which would be kind of neat. If not we would build more smaller ones.
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Post by dragon on Aug 5, 2021 16:43:36 GMT
Humans can survive long-term in 0G just fine with exercise, it's getting them back into 1G that's a problem. There were some very long duration ISS and Mir stays that, among other things, confirmed that. It's unlikely that we're going to see a hard barrier to indefinite 0G survival, barring difficulties with medical procedures. That's not to say centrifuges aren't needed, but that's because most of long-duration spaceflight has landing on some planet as a destination, and that's hard to accomplish when you're acclimatized to 0G.
Now, a Moon base (such as Artemis one, if it happens), will likely supply information about how much low, but non-zero gravity helps. A centrifuge producing lunar-level gravity would be rather easier than making Earth or even Mars gravity.
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Post by airc777 on Aug 8, 2021 18:17:07 GMT
An human can probably survive in zero gravity practically indefinitely, yes. I don't believe you can say that 'humans' in the plural collective can survive in zero gravity indefinitely or that there has been enough study on the subject until after humans have achieved reproducing in zero gravity.
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Post by dragon on Aug 9, 2021 22:56:40 GMT
Human reproduction in microgravity is certainly an unsolved problem, but experiments with other mammals suggest it should work. That said, no experiment has yet involved an animal bred entirely in 0G, and the rats that developed in 0G had trouble orienting themselves (hardly surprising, with no intuitive sense of "up" and "down"). Likely, a mammal born in 0G will have more trouble adjusting to an environment with gravity than the other way around.
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Post by sage on Aug 16, 2021 16:09:38 GMT
Nobody knows, since nobody has ever attempted a medical procedure in anything but 1G. Hence, your actual question has no known answer. In the future, there will likely exist 0G medical procedures. There might be some now, for the ISS, but I suspect they're strictly first aid, if anything serious would happen to one of the crew, he or she would be crammed into a Soyuz and sent back to Earth ASAP. If needed, the ISS crew can get back to Earth in less time than it'd take some people in rural areas to drive to a nearest doctor. The only long-duration flight without this option were the lunar missions, and the plan for these was to send up healthy, strong men and hope they manage to stay like this. I suspect any gravity that you can feel is better than none at all. The more, the better, although in certain situations lower gravity might be medically useful, so on a centrifuge, the medbay would likely extend into low-G areas and have a way of moving the patient between levels. Where it's impossible to generate gravity for the whole ship, compact spin systems like I described might be used to generate localized gravity (of arbitrary strength) in order to enable normal procedures to be enacted. I was hoping you wouldn't say that. Did we not do a lot of medical experiments in space? The only paper I could find on necessary gravity was how much gravity is needed for orientation. How much gravity is enough?
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Post by dragon on Aug 16, 2021 23:17:09 GMT
I was hoping you wouldn't say that. Did we not do a lot of medical experiments in space? The only paper I could find on necessary gravity was how much gravity is needed for orientation. How much gravity is enough? Surprisingly, we didn't. Sending stuff to space is expensive. Living things, much more so. Animal experiments are expensive in general (living aside the bureaucracy and ethics, an animal is a fiendishly complex system with many variables to take into account), and that's the only way we could do such a thing. Medical experiments in space were almost exclusively concerned with how healthy human bodies reacted and adjusted to microgravity and the stresses of a rocket launch. None of them involved things actually going wrong, any health issues are pretty much a ticket back to Earth. Now, this is a very interesting matter, and I'd certainly submit such a grant application if I had a shot at funding for a trip to ISS, but to my knowledge, it's not something that is currently being explored (which is why it's such a great thing to research, citations guaranteed to the first people to run this experiment). If the CAM was launched, it'd have been a perfect place to run this kind of research, but it wasn't.
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Post by sage on Aug 17, 2021 6:02:21 GMT
I was hoping you wouldn't say that. Did we not do a lot of medical experiments in space? The only paper I could find on necessary gravity was how much gravity is needed for orientation. How much gravity is enough? Surprisingly, we didn't. Sending stuff to space is expensive. Living things, much more so. Animal experiments are expensive in general (living aside the bureaucracy and ethics, an animal is a fiendishly complex system with many variables to take into account), and that's the only way we could do such a thing. Medical experiments in space were almost exclusively concerned with how healthy human bodies reacted and adjusted to microgravity and the stresses of a rocket launch. None of them involved things actually going wrong, any health issues are pretty much a ticket back to Earth. Now, this is a very interesting matter, and I'd certainly submit such a grant application if I had a shot at funding for a trip to ISS, but to my knowledge, it's not something that is currently being explored (which is why it's such a great thing to research, citations guaranteed to the first people to run this experiment). If the CAM was launched, it'd have been a perfect place to run this kind of research, but it wasn't. Then the only answer we can come up with then is that we need .15g of earth gravity. This is based on the paper "How much gravity is enough? Team studies astronauts determine 'up' in space" . Last I checked a man mission to mars will have a big problem if we can't do a medical procedure during a trip.
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Post by dragon on Aug 17, 2021 23:08:33 GMT
Then the only answer we can come up with then is that we need .15g of earth gravity. This is based on the paper "How much gravity is enough? Team studies astronauts determine 'up' in space" . Completely different things. Absent anything better, .15g might be a good estimate, but there's no guarantee it's enough. Our spatial orientation depends on just one bodily fluid (and a peculiar one, at that), medical procedures have to deal with many others (in fact, every other fluid except for cerebrospinal fluid and the vitreous, which you don't touch except in cases that require a fully outfitted hospital, anyway). Yes, this question needs to be answered before any manned Mars flights, since Mars isn't a very good environment for exploratory medical research, and we simply don't know what complications might arise when trying to treat any kind of injury in reduced gravity. Most likely, there will be a need for animal experiments in a centrifuge with variable rotation speed, to test different conditions.
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Post by sage on Aug 20, 2021 2:05:35 GMT
Then the only answer we can come up with then is that we need .15g of earth gravity. This is based on the paper "How much gravity is enough? Team studies astronauts determine 'up' in space" . Completely different things. Absent anything better, .15g might be a good estimate, but there's no guarantee it's enough. Our spatial orientation depends on just one bodily fluid (and a peculiar one, at that), medical procedures have to deal with many others (in fact, every other fluid except for cerebrospinal fluid and the vitreous, which you don't touch except in cases that require a fully outfitted hospital, anyway). Yes, this question needs to be answered before any manned Mars flights, since Mars isn't a very good environment for exploratory medical research, and we simply don't know what complications might arise when trying to treat any kind of injury in reduced gravity. Most likely, there will be a need for animal experiments in a centrifuge with variable rotation speed, to test different conditions. What about 0 g on the flight there? Does anyone know what the estimated travel time to Mars? I know it depends on the space ship, but a rough estimate will works as well. Also does not spatial orientation effect medical procedures? And on a animal experiments, did we not do some of those with Kosmos 782 (Bion 3)? Kosmos 782
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