[HN Gopher] Maglev titanium heart inside the chest of a live pat...
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Maglev titanium heart inside the chest of a live patient
Author : thunderbong
Score : 126 points
Date : 2024-07-26 17:51 UTC (2 days ago)
(HTM) web link (newatlas.com)
(TXT) w3m dump (newatlas.com)
| Jyaif wrote:
| > the titanium heart is only meant to keep a patient alive while
| they wait for a heart transplant, which has always been the goal
| of fully mechanical heart development at this stage of the game.
|
| Why are we not aiming higher?
| nightfly wrote:
| Because we can barely get a temporary one working now. I'm sure
| they'd love to be able to make a permanent one, it's just not
| in the cards yet.
| WJW wrote:
| Same reason as why we're not developing starships to go to the
| other side of the Milky way at the moment: We don't know how to
| and the leap from "what we can do right now" (ie we struggle to
| get people to the moon permanently) and "other side of the
| galaxy" is simply too big.
| didgeoridoo wrote:
| This article does a good job of outlining the challenges faced:
| https://www.bbc.com/future/article/20230217-the-61-year-long...
|
| From the outside, it looks like a race between figuring out the
| biocompatibility and power issues for total artificial hearts
| vs. figuring out the immunological issues for xenografts (pig
| hearts, mostly).
|
| If I had to put money on it, I'd bet that the xenografts win.
| It doesn't seem like we've made huge strides toward solving the
| power and durability requirements of total artificial hearts,
| while immunology advances are happening rapidly. Exciting
| times, nonetheless.
| iancmceachern wrote:
| Totally, I've been following that space closely as well.
|
| Amazing times indeed, we are seeing xenografts and artificial
| organs in use.
| TaylorAlexander wrote:
| Would be nice if a pig didn't have to die to save a human
| though. This is not something everyone cares about but some
| people (like me) do care. Hopefully some day we can advance
| the technology enough with artificial solutions.
| didgeoridoo wrote:
| This is honestly a pretty niche concern. Even most
| religions that strictly forbid eating pork make an
| exception if a human's life is at stake.
|
| Your best bet would probably be in advocating for the pigs
| to be engineered to prevent cortical development, ensuring
| they don't become anything beyond twitching, unconscious
| organ bags. In many ways I think people would find this
| more disturbing, though.
| gregoryl wrote:
| Something like 6% to 10% of the population is vegan, a
| bit more than niche!
| HPsquared wrote:
| That sounds high. Are we talking about India here?
| JumpCrisscross wrote:
| > _That sounds high. Are we talking about India here?_
|
| It sounds high even for India. About 40% of Indians are
| vegetarian, a third if we exclude those who eat eggs [1].
| The part of the country where vegetarianism is most
| rampant, the North, is also the highest dairy-consuming
| part of the country [2].
|
| In any case, while medical veganism is something to think
| about, it's not worth prioritising until after we have
| reliable artificial organs.
|
| [1] https://en.wikipedia.org/wiki/Vegetarianism_by_countr
| y#India
|
| [2] https://theprint.in/pageturner/excerpt/there-is-a-
| scientific...
| bluescrn wrote:
| It kind of feels like activists have been trying to erase
| the concept of vegetarianism/pescatarianism in recent
| years while pushing full-on veganism.
|
| That's probably not a good move if we want to achieve a
| pragmatic reduction in meat consumption to help reduce
| related CO2 emissions. A smaller step is a much easier
| sell.
| TaylorAlexander wrote:
| My sincerest hope is that eating animals becomes less
| popular over the next hundred years such that killing
| them for medical needs becomes less acceptable.
| toomuchtodo wrote:
| Growing a human heart from scratch sounds like the ultimate
| bioengineering X prize.
|
| https://www.nhlbi.nih.gov/news/2023/mini-hearts-dish-big-
| win...
|
| https://www.nature.com/articles/s41467-021-25329-5
|
| https://news.stanford.edu/stories/2022/03/building-heart-
| one...
| fuzzfactor wrote:
| >Would be nice if a pig didn't have to die
|
| Something a bacon lover never said ever . . .
| TaylorAlexander wrote:
| tbh I bet plenty of bacon lovers feel bad that a sweet
| intelligent animal dies to make their meal, and if a
| perfect copy of bacon could be made without it I bet a
| good number of them would be happy to switch to it.
| fuzzfactor wrote:
| This does seem like a more "palatable" alternative and
| there should be excellent opportunity for the lab-grown
| pork to have a place on the table. Would seem less cruel
| to a lot of people I would think.
| brnt wrote:
| This bacon lover has seen how pigs are treated in
| industrial facilities and has lost all appetite. I rarely
| buy it, from a local place whose pigs are slaughtered not
| by low wage people in a dark slaughterhouse that must
| meet quotas and have very disturbing ideas of fun.
| fuzzfactor wrote:
| I do know what you mean.
|
| I was raised as a pork lover but did stop as a teenager
| on my own a couple years before I quit beef. I think that
| did have a positive effect on my young health in the
| interim, but eventually everything was replaced by more
| comprehensive plant-based alternatives.
|
| Still love the smell of bacon though.
| tomcam wrote:
| > Why are we not aiming higher?
|
| We've been aiming higher explicitly for at 70+ years
| (https://en.wikipedia.org/wiki/Artificial_heart). I've been
| following it for 50. Artificial hearts were 5 years away since
| at least 1972 or so when I first learned about this field. The
| problems (mechanical, surgical, electrical, biological) are
| endless and it's an astoundingly hostile environment for
| machinery. We have enough problems getting pacemakers to work
| without severe problems.
| Leynos wrote:
| The Abiocor device always fascinated me.
|
| It was developed with long-term implantation in mind. You can
| read about it here:
| https://www.sciencedirect.com/topics/medicine-and-dentistry/...
|
| The use of inductive power transfer meant that no transdermal
| cabling was needed.
|
| Sadly, it sounds like for various reasons the dream was not
| achievable at the time.
| iancmceachern wrote:
| I know people who worked on that, I've held one in my hand.
|
| It was not designed with long term implantation in mind.
|
| It was designed to get funding and keep the company alive.
| The device itself was very crude, not statenof the art at the
| time, and much of it was hand dip-molded with basic
| materials. It was a hand made research device that in all
| reality would have never been expected to be reliable and
| long lasting.
|
| The Bivacor, Heartmate III, these things are in a different
| class.
| iancmceachern wrote:
| The human heart is magical. They've been aiming higher since
| the 60s and this device is also aiming higher, but this is the
| stepping stone to that.
| enthulhusiastic wrote:
| Because our bodies are already peak technology.
|
| I think the 6-million-dollar man thing is a weird goal.
|
| Better to regrow, implant, perhaps supplement.
|
| Full-on replacement isn't just a "when" but a "why" and a "how
| do you expect to do better than evolution".
|
| Titanium is cool! That doesn't make it better than muscle.
|
| Go for a run if you want a better heart
| perihelions wrote:
| - _" how do you expect to do better than evolution"_
|
| Because our goal is aligned with our actual problem (survival
| of individual human beings), as opposed to the merely
| partially-aligned goal of "statistical survival up to
| reproduction age"? Natural evolution is an unaligned AI, in a
| sense: powerful, but not helpful.
|
| Eventually humanity will defeat this problem, and we won't
| even need computational parity with natural evolution to do
| that. Most of that computation is wasted.
| Dylan16807 wrote:
| It's really easy to come up with a better plan than evolution
| for lots of things.
|
| If our bodies were peak, we wouldn't need to use hundred(s)
| of hours of exercise per year to force muscular and
| cardiovascular improvements, it would just happen. Muscles
| wouldn't shrink away in an aggressive attempt to conserve
| calories, especially not regardless of BMI.
| bamboozled wrote:
| _If our bodies were peak, we wouldn 't need to use
| hundred(s) of hours of exercise per year to force muscular
| and cardiovascular improvements, it would just happen._
|
| Then what would be the point of living if you had nothing
| to do but wait for updates? How boring.
|
| Even a self-improving machine is spending time, not
| exercising but "designing a better version of itself".
| Which is an "exercise".
|
| I hate to say this but I think your comment misunderstands
| the beauty of life and the challenge behind the struggle to
| improve. It is a blessed journey.
|
| I personally think being fallable and not having full
| control of my destiny, while scary, is a feature and not a
| bug. It seems to make existence exciting.
| Dylan16807 wrote:
| > nothing to do
|
| > Which is an "exercise".
|
| You're arguing against a strawman. I'm not complaining
| about working for self-improvement, I'm complaining about
| how muscles shrink away so rapidly when not in use. Look
| at what happens when people are bedridden for a few
| weeks, that is not good design!
|
| And I'm not saying people should automatically look like
| body builders, I'm saying the baseline should be a
| healthy level.
| elcritch wrote:
| I'm pro genetic modifications for these sort of (slight)
| changes. We live in entirely different environments and
| our baselines to be healthy makes sense to me. Of course
| the next step always seems to be "make superhuman
| soldiers" or "designer babies".
| bawolff wrote:
| You first must crawl before you can run.
| fuzzfactor wrote:
| Listen to what Dr. Cohn says in the clip:
|
| https://abc13.com/post/artificial-heart-procedure-performed-...
|
| >Why are we not aiming higher?
|
| The final trajectory is not fully known but it looks like they
| have been preparing for a moon shot from the beginning anyway.
|
| You've got to get there from here.
|
| The higher the integrity, the more you under-promise and over-
| deliver :)
|
| not my downvote btw, corrective upvote to compensate
| _qua wrote:
| That white hose you see coming off the back of it is the drive
| line which passes out the chest and connects to an external
| battery. It's not a normal life with one of these in place, a
| heart transplant would be vastly preferable.
| billfruit wrote:
| Is it not possible to avoid the cable passing through the
| chest, by using induction to pass currents between circuits
| inside and outside the body?
| nickburns wrote:
| dupe:
|
| https://news.ycombinator.com/item?id=41086952
| dang wrote:
| Looks like that one was posted later* so we'll merge that
| thread hither. Thanks!
|
| * (you can tell from the item IDs)
| nickburns wrote:
| ah. was confused by the timestamping on my end (i.e. 41080654
| shows just '2 hours ago' and 41086952 shows '7 hours ago').
| must be some other inner-workings. but thanks for pointing
| out IDs to me for future reference.
| dang wrote:
| That's an artifact of HN's re-upping system. The system is
| described at https://news.ycombinator.com/item?id=26998308
| and links back from there. About the timestamps, there are
| past explanations here: https://hn.algolia.com/?dateRange=a
| ll&page=0&prefix=true&que.... I hope that will make sense!
| ajb wrote:
| Wonder how the join the arteries to it. Any pressure seems likely
| to kill biological tissue, and while it might grow on, presumably
| that would take a while. Maybe some kind of glue?
| iancmceachern wrote:
| They have what they call sewing cuffs attached to short
| arterial and venous grafts which you can get already for
| surgical repair of blood vessels. The sewing cuffs are
| essentially little cuffs made from polyester velour and
| silicone and then the surgeon sews through the flanges on the
| cuffs to anastomose to the blood vessels.
|
| Here is a paper that talks about it for LVADs, which are
| similar but different
|
| https://link.springer.com/article/10.1007/s10047-022-01350-3
| floam wrote:
| The BiVACOR titanium artificial heart is sutured to the
| arteries, not glued. Surgeons use biocompatible synthetic graft
| materials (like Dacron or ePTFE) to connect the arteries to the
| device.
| iancmceachern wrote:
| Sometimes they use bioglue to cover up mistakes in their
| sewing, they're not supposed to, and you certainly can't do
| things like put bioglue all around the circumference, but my
| understanding is that it's used for touch up here and there.
| floam wrote:
| That's interesting, thank you for the gentle correction and
| illuminating that caveat. I just shouldn't make assertions
| about topics I have no background with when I know I just
| read about this on Google Scholar right before commenting.
| I'm basically confidently faking it like ChatGPT.
|
| "ah they stitch it to this neat synthetic graft stuff
| therefore glue couldn't/wouldn't be used": wrong.
| alecst wrote:
| Wow. I really appreciate the humility and candor shown by
| you in response to being corrected. I'm genuinely
| impressed.
| perihelions wrote:
| - _"...active control system... "_
|
| https://spectrum.ieee.org/this-maglev-heart-could-keep-cardi...
|
| That's some high-stakes software programming!
|
| Passively-stable magnetic levitation is possible with diamagnetic
| materials (notably including superconductors), but those probably
| don't meet the requirements of this project.
|
| - _" This positional control system works as follows: Tiny
| contactless sensors send out magnetic fields that interact with
| the rotor, determining its exact location many times per second.
| If the rotor is moving in one direction or another, the control
| system puts electrical energy into electromagnetic coils within
| several actuators, causing them to cancel out that movement."_
| elromulous wrote:
| Yes, but not as high-stakes as an autopilot in a commercial
| aircraft!
| argiopetech wrote:
| Perhaps, but there are a pilot and first officer to take over
| if the autopilot goes out. You better be in the OR if your
| titanium heart tries to kill you...
| iancmceachern wrote:
| Exactly. And systems for commercial aircraft are actually
| designed (by law) to be dual fault tolerant. This means that
| all safety critical systems on an airliner need to have 3
| filly redundant, independent systems and each needs to be
| able to function without the other two.
|
| In even class III (implantable and safety critical meaning
| the patient is harmed or killed if they fail) medical devices
| are only required to be single fault tolerant.
| haswell wrote:
| This writeup is significantly better than the OP link. Should
| probably be the article of record.
|
| The section on constant flow vs. variable flow to simulate a
| heartbeat got me thinking about how weird it would feel to have
| no pulse, or what it'd be like to experience a moment of
| excitement/adrenaline without the accompanied pounding in my
| chest.
| JumpCrisscross wrote:
| What are the consequences of a rotor "crash"?
| yumraj wrote:
| This gives a new meaning to _heavy heart_
| low_tech_punk wrote:
| It's cool and spooky that the patient will no longer have heart
| beat, because the rotor will deliver continuous blood flow.
| JoshTriplett wrote:
| I've read a number of reports about that. Apparently it's a
| little unnerving at first, but the biggest problem is that they
| have to make sure that any medical professionals or people they
| know are aware that they don't have a heartbeat and _that 's
| expected and does not mean they need CPR_.
|
| Also, there's a long-term question of whether there are any
| processes within the body are keyed off of the heartbeat,
| because biological designs are often spaghetti and take full
| advantage of any random interaction and make it load-bearing.
| LelouBil wrote:
| The workings of our bodies are just the xkcd "holding
| spacebar makes the computer overheat" on a giant scale.
| mystified5016 wrote:
| The regulation of any individual process in the body is a
| rube goldbergian nightmare of hormones and
| neurotransmitters and things that _just happen_ to fire
| under the right conditions.
|
| I have absolutely no doubt that _something_ in the body
| relies on a periodic heartbeat in some fashion, but it
| seems so far to not be anything particularly critical.
| loa_in_ wrote:
| Probably passive lymph pumping in organs that aren't
| muscular
| TeMPOraL wrote:
| Agreed. Hell, it wouldn't surprise me if some part of
| human neurology used heartbeat as a clock signal
| (particularly aspects that would benefit from speeding up
| in same situations the heart does).
| tangjurine wrote:
| Ah, so like my codebase
| oooyay wrote:
| I have a heart abnormality that shows up as an inverted
| T-wave on an echo cardiogram. Some physicians will
| immediately think I'm having some sort of heart attack,
| though I display no symptoms. It's actually that my heart
| fills fully and empties fully in a single cycle. I'm not a
| medical professional, so all I have are laymans explanations,
| but what it means is that my heart beats less frequently but
| stronger than the average heart. It was documented thoroughly
| throughout my time in the Marines and a cardiologist
| suggested it wasn't a defect. My heart rate remains much
| lower than other peoples when under stress and my heart rate
| at rest is only slightly lower than an average persons. When
| I asked him what all that meant he suggested that I probably
| won't die of anything heart related, but my body is otherwise
| normal.
| bluesroo wrote:
| If you don't mind me asking, what is your blood pressure
| with this abnormality? My gut feeling would be that it you
| have a much larger gap between your systolic and diastolic
| numbers than average?
| hnburnsy wrote:
| Get that tattooed on the chest.
| dtgriscom wrote:
| I wouldn't be surprised if the lack of pressure fluctuations
| would cause harm in the long run (although this isn't meant for
| the long run).
|
| Hearts have been beating for a very, very long time, and I'm
| sure other biological structures have taken advantage of that.
| HPsquared wrote:
| I wonder if they prescribe something like walking or jogging
| as a substitute "repetitive movement" to get things moving.
| iancmceachern wrote:
| This is a whole thing. Look up "pump head". Also check out:
|
| https://ventriflo.com/
| jnurmine wrote:
| As I've understood it, not having a pulse creates all kinds
| of problems, blood clots and whatnot. It's simply not good
| for the blood, nor the blood flow. The body isn't made for
| it.
|
| Pulsatile flow doesn't have such issues, so a Swedish company
| called Real Heart is making a TAH that pulses like a heart.
|
| So far they've done successful tests with sheep and tons of
| testing of various blood parameters which look way better
| than traditional continuous-flow TAHs. Clinical trials on
| humans should be coming up relatively soon.
|
| I hope they make it, and can improve it and make it smaller
| to fit children etc. It's pretty interesting technology.
| alan-hn wrote:
| Here is one from Carmat that is already in use in Europe
|
| https://www.carmatsa.com/en/our_product/
| rediguanayum wrote:
| Here's a video where Bivacor is working on making their
| impeller design simulate a pulse:
| https://youtu.be/3uV8XZcIBbk?si=I9Gf6pEd9v71Q7JJ. Also has
| nice interview with the inventor/founder Daniel Timms where
| he talks about the motivation for doing this companany i.e.
| when his dad got heart failure.
| haswell wrote:
| > _Such a pump has no valves, so a patient using the Bivacor
| heart in its most basic mode would have no pulse. But we
| recently adapted our device to give it a pulsatile outflow
| option._
|
| > _The pump can run at constant speed, producing continuous
| blood flow at a constant pressure, and in our early experiments
| we concentrated on testing this "pulseless" mode. But it's easy
| to change its speed, and our later experiments proved that
| controlled speed changes could produce a wide range of flow and
| pressure characteristics. Running the pump first at high speed
| (sending out more blood) and then at low speed (sending out
| less) creates something resembling a biological heart's pulse;
| rapidly alternating these two speeds creates something that
| looks like a normal heartbeat._
|
| > _We're now working primarily in that pulsatile mode. Within
| cardiology, there's an open debate about whether a pulse is
| necessary for good health..._ [0]
|
| The ieee.org article has significantly more detail and is a
| fascinating read.
|
| - [0] https://spectrum.ieee.org/this-maglev-heart-could-keep-
| cardi...
| _qua wrote:
| The lack of pulsatile flow is associated with formation of AV
| malformations in the colon which can cause GI bleeding which is
| a more than a little problem when you have a piece of hardware
| in your chest which requires you take anticoagulants.
| guidedlight wrote:
| Soon after the procedure a donor organ became available, so
| they no longer have the artificial heart.
| aussieguy1234 wrote:
| If you live long enough, everyone's heart will give out
| eventually. With a sufficiently advanced artificial one, maybe
| not?
| JumpCrisscross wrote:
| This video helped me understand what's going on:
| https://www.youtube.com/watch?v=HAajHSmplpA
| MOARDONGZPLZ wrote:
| Really disappointed comments are turned off on this video.
| donaldcuckman wrote:
| So this is actually something I've worked on for 3ish years. Not
| this project but a similar BiVAD. Pictured is a dual centrifugal
| pump. The actual impeller is probably 20mm in diameter. The
| maglev/ pump portion is most likely a slice motor topology. Which
| is passively stable axially.
| _qua wrote:
| This is not the first cardiac support device using maglev
| technology. Some LVAD devices and Impella pumps also use maglev.
| ranger_danger wrote:
| Zip-ties: FDA certified to keep your heart running smoothly. /s
| fuzzfactor wrote:
| And the arteries of your circulatory system well organized as
| you bundle your ethernet wires :)
| 8f2ab37a-ed6c wrote:
| Genuinely glad we're slowly approaching Syndicate-level body
| mods, this can't come soon enough.
| bumbledraven wrote:
| https://bivacor.com/
| userbinator wrote:
| Maybe this is the first time this technology has been used in an
| artificial heart, but "maglev" pumps are not new --- they've been
| around for at least a few decades. It's known as "wet rotor
| bearingless" in existing literature, and they are found in
| numerous white goods such as dishwashers, washing machines, HVAC
| systems, as well as aquariums and computer water cooling. Usually
| the drive electronics are the failure point.
|
| Here's an article from 2002 about this type of pump:
| http://www.mech.ibaraki.ac.jp/~ismb8/pocpdf/0001.pdf
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