10 ms·

New generation artificial heart implanted in patient

142 points by jacobrussell 5y ago

01100011 5y ago
Interesting to see that it uses bovine derived valves. Does anyone know the reason for that? Are real tissues less likely to cause issues with blood coagulation or have materials coatings caught up enough to solve that problem? Does anyone know where modern thinking on the role of the heart is headed? I was intrigued to run across this article discussing the heart's role as more of a hydraulic ram and less of a pump: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5215277/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5215277/ I don't suppose the science is settled, but it is interesting that in the modern age we're still debating the function of such an important organ.
- deleted 5y ago
  [deleted]
- atty 5y ago
  You’d need to ask a cardiologist of course, but I think for all intents and purposes, the science is in fact settled. The heart pumps blood. In any field you see people using weak evidence to question strongly evidenced positions like in the linked article. I worked as a physicist for 7 years or so, and you frequently saw people using small deviations in experimental results to try and question general relativity, or parts of the standard model. Of course, when you see the few outliers lined up it seems convincing, but if you work professionally in the field you realize that that’s what they are - outliers. Just a handful of strange results in a literal flood of results that fit within and support the status quo. And, fortunately or unfortunately, if you’ve seen it happen to someone, I think the evidence that the heart pumps blood is extremely convincing, having witnessed it first hand - if your heart stops, blood stops flowing. And we know that that is the correct order of causation, because to fix it, you shock the heart into pumping again. You’d need FAR stronger evidence than failed drug trials (the vast majority of drug trials fail) or failed device trials (the vast majority of device trials fail) to seriously weaken that position, as far as I’m aware.
  - profile53 5y ago
    I think you misunderstood the parent comment's argument. What I believe they were saying is that continuous pumping (i.e. rotary pumps) may be less effective than beat-by-beat pumping (i.e. pulsatile pumps). The former result in a static continuous blood pressure while the latter result in a blood pressure waveform with a systolic and diastolic pressure. The argument I'm familiar with is that peaks and valleys in blood pressure trigger strengthening of arterial walls in a similar mechanism to muscle growth. But, there's a few different arguments and as far as I know, the science isn't completely settled.
    - robbiep 5y ago
      Pulsating vessels are really important. There’s a bunch of evidence of the physiological benefits to having a pulse. Doesn’t mean you can’t, but it’s good for you, you evolved to have it. You can convince stem cells to differentiate into arterial wall just by exposing them to arterial flow. Just as you can get stem cells differentiate into osteoblasts by keeping them in a rigid structure. Smart fuckers
      - lostlogin 5y ago
        > There’s a bunch of evidence of the physiological benefits to having a pulse. This is such a great statement on a couple of levels. That having no pulse and being alive is even possible is amazing. How basic medical observations are done for these people is interesting to contemplate.
- superjan 5y ago
  The vast majority of replacement valves implanted today also use animal tissue (bovine and pig). They are much more similar to the original valves than metal replacements.
- c-slice 5y ago
  mechanical heart valves require patients to be on blood thinners for the rest of their life, bovine and porcine heart valves are most similar to human heart valves in size and shape and they have very good reliability without requiring the patient to continue taking blood thinners.
  - aetherspawn 5y ago
    It is fascinating that we can't reproduce the mechanical properties of a small biological valve, even a dead one (they are 'killed' before they are implanted). When they finally do figure it out, imagine all the various applications to improve the longevity of ... well, everything.
    - elric 5y ago
      We can't even design water pipes and valves that don't degrade over time. Limescale builds up and clogs the works. There's only a tiny amount of minerals in water, and yet that happens. Blood -- as they say -- is much thicker than water, and contains components specifically designed to clot. It's not wonder that this is a tricky problem to solve.
      - hellbannedguy 5y ago
        That's basically in galvanized pipe, or steel pipe.
  - signa11 5y ago
    yup that is correct. however non-mechanical valves last typically for 10 to 15 years, and will require a surgery past that time period. some studies[1] have shown the mechanical valves are the safest choice. 1. https://med.stanford.edu/news/all-news/2017/11/mechanical-heart-valve-often-the-safest-choice.html https://med.stanford.edu/news/all-news/2017/11/mechanical-he...
    - wombatpm 5y ago
      There is also a difference in failure modes. Natural valves degrade performance overtime due to calcification of the valve, giving you warning and time to make decisions over replacement. Mechanical valves fail catastrophically by either remaining stuck open or having the valve plate shatter. If you ever stop hearing your valve click you need to get to a hospital ASAP
- profile53 5y ago
  Metal valves are only used in the young (i.e. under 50) because they are the most durable and can last a lifetime. The caveat is that lifelong blood thinners are needed because the metal provides a surface for clots to form. Bovine valves are the typical favorite because the body does not form clots on a bovine valve. They're usually sterilized and all cells killed so that it doesn't trigger tissue rejection. In the end, it's just a connective tissue matrix. Unfortunately, this means it is less durable and cannot heal from damage so they only last 10-15 years.
  - robbiep 5y ago
    That’s not really true around selection of valve, it’s all about fitness. A lot of younger people will have tissue valves, because they can have another one after (probably, if they don’t have too many Comorbidities) and it’s a better trade off than being anticoagulated. A though some of the newer anti coagulants are much less of a pain in the arse to be on than 10 years ago. Also they tick, which some people don’t like. Similarly, many cardiologists would give a 80 year old a tissue valve because they probably won’t need another one and again the anti coagulation trade offs work in their favour
    - profile53 5y ago
      You’re right — what I said was an oversimplification and a little bit untrue. I agree fitness and Compton dotier are a huge factor in selection of valve type. That said, in my experience, cardiologists are really hesitant to use a tissue valve in someone under 50, especially if it is an open heart procedure. With an open heart, the adhesions (scar tissue) on a revision surgery makes it far riskier and less likely to heal well. So the follow up for a valve replacement after 10-20 years becomes much more high risk. Not a problem if they’re 70 and they would be 90 at the time a replacement is needed. Much more of a problem if they’re 30 and will likely need 4-5 artificial valves in their lifetime. The new thing is to first do a TAVR/TPVR, which involves cutting into an artery - most commonly the leg - and placing a valve by routing it through the artery into the heart. But, any revision will need to be an open heart procedure. So the first replacement is trans catheter, then the second is open heart. Thus, the third replacement gets much more risky. So, if someone is 50, the second replacement is at 65, and the third would be at 85, so not a huge issue. By contrast, if they’re 30, the high risk 3rd surgery will happen at 65.
- robbiep 5y ago
  You use bovine or porcine generally. They last about 10 years. Metal valves last 30 years but require anti coagulation. Since porcine and bovine valves are zero from à immunogenicity standpoint, they’re ideal unless we could get human ones that are plugged into the circulatory system. Although with a pump heart you’re going to be on blood thinners anyway. And probably a few other things. The dream of where the heart is headed is to growing new ones. The best heart is a human heart suited to you
  - sizzle 5y ago
    If they only last 10 years.. they have to cut you open to replace them assuming you live a few decades??
    - robbiep 5y ago
      They last 10 years ‘or so…’ some up to 17-20, so there’s a variability there, but they fail gracefully so you can monitor which is nice (as another commenter pointed out). Tou can replace with transcutaneous valve replacement (like a stent, through a blood vessel) or open operation
tacon 5y ago
The Texas Medical Center is moving ahead on its Bivacor rotary pump artificial heart.[0] It does not appear that Bivacor is a bridge to a transplant, but rather an end point. They kept a cow alive for many months a few years ago. Since it is a continuous rotary pump, the patient will have no pulse with this device. One of the inventors behind Bivacor is Dr. Billy Cohn, an elite heart surgeon with a strong bent toward innovation. He would have an idea, hit his garage to cut up some plastic mesh, seal it, sterilize it, and be trying it in a patient in a few days. He jokes about Home Depot being his best source of medical equipment. In fact, he tells a hilarious Home Depot story in the middle of his standard talk on medical innovation.[1] [0] https://www.bizjournals.com/houston/news/2021/05/19/bivacor-medical-device-artificial-heart-funding.html https://www.bizjournals.com/houston/news/2021/05/19/bivacor-... [1] https://youtu.be/iHTVTU8PPGk?t=623 https://youtu.be/iHTVTU8PPGk?t=623
- lugged 5y ago
  I wonder if a pulse is required for any bodily functions we're not aware of, body tends to regulate a few rhythms.
  - laser 5y ago
    Pulse is central to traditional Indian medicine (Ayurveda) [1]. Will be interesting to see what the science finds, although I wouldn’t personally volunteer to have a pumpless-heart. Sounds likely to have unintended consequences as you suggest. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4890095/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4890095/
    - sokoloff 5y ago
      People aren’t “volunteering” for this in any meaningful way. Their next-best option is pretty terrible.
  - elric 5y ago
    I remember reading, years ago, about someone who was temporarily fitted with a rotary pump. He said his hearing required some adjustment, apparently we sort of constantly hear blood rushing without being aware of it, but that somehow changes when your pulse is gone. How do these pumps affect blood pressure? Does it become constant? That can't be good for the elasticity of arteries & veins?
villgax 5y ago
Tiny nuclear hearts is the future
- aetherspawn 5y ago
  I have a feeling there isn’t enough power in nuclear at the scale that would fit inside the body with sufficient shielding. Nuclear is surely for low power devices, but human hearts would actually use a great deal of power (estimate 50-100W). It won’t last for years like you’d expect. Even if you _can_ package it, still needs batteries for redundancy and clearly those don’t fit inside either. Patients with batteries carry around massive backpacks. Brings a new meaning to ‘having a meltdown’ though. Overheating nuclear heart would literally boil your blood.
  - Someone 5y ago
    On https://hypertextbook.com/facts/2003/IradaMuslumova.shtml https://hypertextbook.com/facts/2003/IradaMuslumova.shtml, the highest estimate there is 5W, and that’s an outlier on that page. That may be because of the difference between output power and input power needed to produce it. One citation there says the mechanical efficiency of the heart is about 20%.
    - aetherspawn 5y ago
      It’s pretty easy to calculate if we knew how long the battery lasts. We can estimate the size of the battery from the weight of the backpack (6kg) and use the time to flat to estimate the power draw - that’s the actual electrical energy usage of the heart.
    - iancmceachern 5y ago
      Exactly, the human heart is a marvel of design and performance. Typically these devices use between 10-30 watts of power for each side of the heart (in the LVAD case). For an artificial heart (which is two LVADs, basically a LVAD and a RVAD) it's more like 30-60 watts of continuous power. The human heart is amazing.
  - 5y ago
habibur 5y ago
I really feel for those that receive these implants and live with it for a few days more. The first such implant receiver lived for 3 months only. The next one maybe 1.5 years. Personally I would have preferred to die rather than put a battery and pump inside my body as a heart.
- wetpaws 5y ago
  >Personally I would have preferred to die You do, someone else would not. I don't see any issues with this, it's not a zero sum game.
- Majestic121 5y ago
  I have trouble understanding your point of view. Implanting an artificial heart is, like most surgical operations, a risky endeavor, especially for the first persons who are taking the most risks (and also helping the most to develop our knowledge). The people choosing to have a new heart implanted do so with full knowledge of the risks, and potential reward (more time alive, helping to develop a new life saving technology/procedure, etc...). If I get a serious disease that requires me to have a dangerous operation, I would love to have the choice to do so, instead of having to endure the disease with no choice. I understand 'feeling' for people that have cardiac issues, but I cannot understand 'feeling' specifically for people that have cardiac issues and choose to undergo a risky and potentially saving surgery.
- bserge 5y ago
  I'd live 3 months just to be a cyborg, that's pretty cool. Maybe overdrive the thing and see if I can be harder, better, faster, stronger. Sadly, all of that would likely be painful, so it's just a daydream.
- iancmceachern 5y ago
  There are people with Heartmate II's (LVADS not artificial hearts, so a bit different) that have lived 10+ years on the devices, with a very high quality of life. That's worth it in my view.
kypro 5y ago
As a layman creating a reliable pump that runs on a battery seems like it would be a fairly easy job for with modern technology. Of course anything mechanical is going to require regular maintenance, but again I wouldn't expect this to be a difficult problem. What are the complications here? Size? Preventing infection? Does it need to adjust flow rate based on oxygen requirements?
- jstanley 5y ago
  One of the complications is that if it stops working, you don't really have time to fix it before you die.
- readams 5y ago
  The biggest ones are blood clotting and the mechanical action destroying blood cells.
- iancmceachern 5y ago
  The challenge isn't in building a reliable pump. The challenge is in the connection between the pump and the human body. If we just put a highly polished titanium tube in the circulation there will be blood clots, hemolysis, and other blood damage. Over time these problems become the main hurdle in getting these types of devices to work.
The_rationalist 5y ago
What improvements and regressions does it have versus the old gen "well established" commercialized artificial heart?
- parsecs 5y ago
  I'm not sure why this post is flagged and dead. This seem like a genuine and constructive question.
- iancmceachern 5y ago
  Lots. The old gen, the only approved one, is actually the continuation of the Jarvik 7 made famous by the Barney Clark case. They've been making and using it all this time. It's now called Syncardia. It's pneumatic and the patients have to carry around a bit pneumatic driver that makes quite a bit of noise during every heartbeat. Patients have large air lines running in and out of their chest to carry the air in and out to drive the diaphragm based pump. It works, bit is not ideal in many ways.
  - The_rationalist 5y ago
    I didn't knew about the pneumatic and noise annoyance, thanks for sharing
albertTJames 5y ago
How they spin it as a duke achievement is ridiculously vain. They were not the one inventing the tech nor the first to implant it.
korse 5y ago
Does anyone have information about the 'external power supply' of the heart in the linked article? I've found some info that is years out of date and I'm wondering how unobtrusive the unit is now.
- iancmceachern 5y ago
  Yes, typically they include circuitry/ICs for brushless motor controller to spin the thing, plus a few more "motor" controllers if they have active magnetics for bearings, or other reasons. This needs to all be redundant, or otherwise safe in the mission critical sense. Then they have batteries, and all the stuff that goes with connecting the two (power regulation, conditioning, etc) and alarms, etc.
ed25519FUUU 5y ago
> The Duke patient ... was referred to Duke in June after a sudden, unexpected diagnosis of heart failure. Moore and his wife, Rachel, recently adopted their two-year-old foster son, Marshall, and arrived at Duke expecting only to undergo heart bypass surgery. 39-year-old admitted to the hospital with unexpected heart failure? Is there more to this story? Is this possibly related to the myocarditis being reported with some mRNA reactions?
- iancmceachern 5y ago
  There are also virus' that attack the heart directly, a few other things that can cause this.
throwitaway1235 5y ago
First artificial heart inventor - https://en.m.wikipedia.org/wiki/Vladimir_Demikhov https://en.m.wikipedia.org/wiki/Vladimir_Demikhov (Albeit non-human)
12bits 5y ago
I just want something like this for my next kidney transplant, I'm so sick of the meds, yes I'm blessed to be alive and living a really good life, but man the 2nd kidney is starting to give me anxiety. Context: Transplant isn't a cure to my autoimmune disease, it will slowly pick away at the graft and have me needing another. Love reading about this kind of stuff.

142 points by jacobrussell 5y ago

Interesting to see that it uses bovine derived valves. Does anyone know the reason for that? Are real tissues less likely to cause issues with blood coagulation or have materials coatings caught up enough to solve that problem? Does anyone know where modern thinking on the role of the heart is headed? I was intrigued to run across this article discussing the heart's role as more of a hydraulic ram and less of a pump: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5215277/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5215277/ I don't suppose the science is settled, but it is interesting that in the modern age we're still debating the function of such an important organ.

deleted 5y ago
[deleted]
atty 5y ago
You’d need to ask a cardiologist of course, but I think for all intents and purposes, the science is in fact settled. The heart pumps blood. In any field you see people using weak evidence to question strongly evidenced positions like in the linked article. I worked as a physicist for 7 years or so, and you frequently saw people using small deviations in experimental results to try and question general relativity, or parts of the standard model. Of course, when you see the few outliers lined up it seems convincing, but if you work professionally in the field you realize that that’s what they are - outliers. Just a handful of strange results in a literal flood of results that fit within and support the status quo. And, fortunately or unfortunately, if you’ve seen it happen to someone, I think the evidence that the heart pumps blood is extremely convincing, having witnessed it first hand - if your heart stops, blood stops flowing. And we know that that is the correct order of causation, because to fix it, you shock the heart into pumping again. You’d need FAR stronger evidence than failed drug trials (the vast majority of drug trials fail) or failed device trials (the vast majority of device trials fail) to seriously weaken that position, as far as I’m aware.
- profile53 5y ago
  I think you misunderstood the parent comment's argument. What I believe they were saying is that continuous pumping (i.e. rotary pumps) may be less effective than beat-by-beat pumping (i.e. pulsatile pumps). The former result in a static continuous blood pressure while the latter result in a blood pressure waveform with a systolic and diastolic pressure. The argument I'm familiar with is that peaks and valleys in blood pressure trigger strengthening of arterial walls in a similar mechanism to muscle growth. But, there's a few different arguments and as far as I know, the science isn't completely settled.
  - robbiep 5y ago
    Pulsating vessels are really important. There’s a bunch of evidence of the physiological benefits to having a pulse. Doesn’t mean you can’t, but it’s good for you, you evolved to have it. You can convince stem cells to differentiate into arterial wall just by exposing them to arterial flow. Just as you can get stem cells differentiate into osteoblasts by keeping them in a rigid structure. Smart fuckers
    - lostlogin 5y ago
      > There’s a bunch of evidence of the physiological benefits to having a pulse. This is such a great statement on a couple of levels. That having no pulse and being alive is even possible is amazing. How basic medical observations are done for these people is interesting to contemplate.
superjan 5y ago
The vast majority of replacement valves implanted today also use animal tissue (bovine and pig). They are much more similar to the original valves than metal replacements.
c-slice 5y ago
mechanical heart valves require patients to be on blood thinners for the rest of their life, bovine and porcine heart valves are most similar to human heart valves in size and shape and they have very good reliability without requiring the patient to continue taking blood thinners.
- aetherspawn 5y ago
  It is fascinating that we can't reproduce the mechanical properties of a small biological valve, even a dead one (they are 'killed' before they are implanted). When they finally do figure it out, imagine all the various applications to improve the longevity of ... well, everything.
  - elric 5y ago
    We can't even design water pipes and valves that don't degrade over time. Limescale builds up and clogs the works. There's only a tiny amount of minerals in water, and yet that happens. Blood -- as they say -- is much thicker than water, and contains components specifically designed to clot. It's not wonder that this is a tricky problem to solve.
    - hellbannedguy 5y ago
      That's basically in galvanized pipe, or steel pipe.
- signa11 5y ago
  yup that is correct. however non-mechanical valves last typically for 10 to 15 years, and will require a surgery past that time period. some studies[1] have shown the mechanical valves are the safest choice. 1. https://med.stanford.edu/news/all-news/2017/11/mechanical-heart-valve-often-the-safest-choice.html https://med.stanford.edu/news/all-news/2017/11/mechanical-he...
  - wombatpm 5y ago
    There is also a difference in failure modes. Natural valves degrade performance overtime due to calcification of the valve, giving you warning and time to make decisions over replacement. Mechanical valves fail catastrophically by either remaining stuck open or having the valve plate shatter. If you ever stop hearing your valve click you need to get to a hospital ASAP
profile53 5y ago
Metal valves are only used in the young (i.e. under 50) because they are the most durable and can last a lifetime. The caveat is that lifelong blood thinners are needed because the metal provides a surface for clots to form. Bovine valves are the typical favorite because the body does not form clots on a bovine valve. They're usually sterilized and all cells killed so that it doesn't trigger tissue rejection. In the end, it's just a connective tissue matrix. Unfortunately, this means it is less durable and cannot heal from damage so they only last 10-15 years.
- robbiep 5y ago
  That’s not really true around selection of valve, it’s all about fitness. A lot of younger people will have tissue valves, because they can have another one after (probably, if they don’t have too many Comorbidities) and it’s a better trade off than being anticoagulated. A though some of the newer anti coagulants are much less of a pain in the arse to be on than 10 years ago. Also they tick, which some people don’t like. Similarly, many cardiologists would give a 80 year old a tissue valve because they probably won’t need another one and again the anti coagulation trade offs work in their favour
  - profile53 5y ago
    You’re right — what I said was an oversimplification and a little bit untrue. I agree fitness and Compton dotier are a huge factor in selection of valve type. That said, in my experience, cardiologists are really hesitant to use a tissue valve in someone under 50, especially if it is an open heart procedure. With an open heart, the adhesions (scar tissue) on a revision surgery makes it far riskier and less likely to heal well. So the follow up for a valve replacement after 10-20 years becomes much more high risk. Not a problem if they’re 70 and they would be 90 at the time a replacement is needed. Much more of a problem if they’re 30 and will likely need 4-5 artificial valves in their lifetime. The new thing is to first do a TAVR/TPVR, which involves cutting into an artery - most commonly the leg - and placing a valve by routing it through the artery into the heart. But, any revision will need to be an open heart procedure. So the first replacement is trans catheter, then the second is open heart. Thus, the third replacement gets much more risky. So, if someone is 50, the second replacement is at 65, and the third would be at 85, so not a huge issue. By contrast, if they’re 30, the high risk 3rd surgery will happen at 65.
robbiep 5y ago
You use bovine or porcine generally. They last about 10 years. Metal valves last 30 years but require anti coagulation. Since porcine and bovine valves are zero from à immunogenicity standpoint, they’re ideal unless we could get human ones that are plugged into the circulatory system. Although with a pump heart you’re going to be on blood thinners anyway. And probably a few other things. The dream of where the heart is headed is to growing new ones. The best heart is a human heart suited to you
- sizzle 5y ago
  If they only last 10 years.. they have to cut you open to replace them assuming you live a few decades??
  - robbiep 5y ago
    They last 10 years ‘or so…’ some up to 17-20, so there’s a variability there, but they fail gracefully so you can monitor which is nice (as another commenter pointed out). Tou can replace with transcutaneous valve replacement (like a stent, through a blood vessel) or open operation

tacon 5y ago

The Texas Medical Center is moving ahead on its Bivacor rotary pump artificial heart.[0] It does not appear that Bivacor is a bridge to a transplant, but rather an end point. They kept a cow alive for many months a few years ago. Since it is a continuous rotary pump, the patient will have no pulse with this device. One of the inventors behind Bivacor is Dr. Billy Cohn, an elite heart surgeon with a strong bent toward innovation. He would have an idea, hit his garage to cut up some plastic mesh, seal it, sterilize it, and be trying it in a patient in a few days. He jokes about Home Depot being his best source of medical equipment. In fact, he tells a hilarious Home Depot story in the middle of his standard talk on medical innovation.[1] [0] https://www.bizjournals.com/houston/news/2021/05/19/bivacor-medical-device-artificial-heart-funding.html https://www.bizjournals.com/houston/news/2021/05/19/bivacor-... [1] https://youtu.be/iHTVTU8PPGk?t=623 https://youtu.be/iHTVTU8PPGk?t=623

lugged 5y ago
I wonder if a pulse is required for any bodily functions we're not aware of, body tends to regulate a few rhythms.
- laser 5y ago
  Pulse is central to traditional Indian medicine (Ayurveda) [1]. Will be interesting to see what the science finds, although I wouldn’t personally volunteer to have a pumpless-heart. Sounds likely to have unintended consequences as you suggest. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4890095/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4890095/
  - sokoloff 5y ago
    People aren’t “volunteering” for this in any meaningful way. Their next-best option is pretty terrible.
- elric 5y ago
  I remember reading, years ago, about someone who was temporarily fitted with a rotary pump. He said his hearing required some adjustment, apparently we sort of constantly hear blood rushing without being aware of it, but that somehow changes when your pulse is gone. How do these pumps affect blood pressure? Does it become constant? That can't be good for the elasticity of arteries & veins?

villgax 5y ago

Tiny nuclear hearts is the future

aetherspawn 5y ago
I have a feeling there isn’t enough power in nuclear at the scale that would fit inside the body with sufficient shielding. Nuclear is surely for low power devices, but human hearts would actually use a great deal of power (estimate 50-100W). It won’t last for years like you’d expect. Even if you _can_ package it, still needs batteries for redundancy and clearly those don’t fit inside either. Patients with batteries carry around massive backpacks. Brings a new meaning to ‘having a meltdown’ though. Overheating nuclear heart would literally boil your blood.
- Someone 5y ago
  On https://hypertextbook.com/facts/2003/IradaMuslumova.shtml https://hypertextbook.com/facts/2003/IradaMuslumova.shtml, the highest estimate there is 5W, and that’s an outlier on that page. That may be because of the difference between output power and input power needed to produce it. One citation there says the mechanical efficiency of the heart is about 20%.
  - aetherspawn 5y ago
    It’s pretty easy to calculate if we knew how long the battery lasts. We can estimate the size of the battery from the weight of the backpack (6kg) and use the time to flat to estimate the power draw - that’s the actual electrical energy usage of the heart.
  - iancmceachern 5y ago
    Exactly, the human heart is a marvel of design and performance. Typically these devices use between 10-30 watts of power for each side of the heart (in the LVAD case). For an artificial heart (which is two LVADs, basically a LVAD and a RVAD) it's more like 30-60 watts of continuous power. The human heart is amazing.
- 5y ago

habibur 5y ago

I really feel for those that receive these implants and live with it for a few days more. The first such implant receiver lived for 3 months only. The next one maybe 1.5 years. Personally I would have preferred to die rather than put a battery and pump inside my body as a heart.

wetpaws 5y ago
>Personally I would have preferred to die You do, someone else would not. I don't see any issues with this, it's not a zero sum game.
Majestic121 5y ago
I have trouble understanding your point of view. Implanting an artificial heart is, like most surgical operations, a risky endeavor, especially for the first persons who are taking the most risks (and also helping the most to develop our knowledge). The people choosing to have a new heart implanted do so with full knowledge of the risks, and potential reward (more time alive, helping to develop a new life saving technology/procedure, etc...). If I get a serious disease that requires me to have a dangerous operation, I would love to have the choice to do so, instead of having to endure the disease with no choice. I understand 'feeling' for people that have cardiac issues, but I cannot understand 'feeling' specifically for people that have cardiac issues and choose to undergo a risky and potentially saving surgery.
bserge 5y ago
I'd live 3 months just to be a cyborg, that's pretty cool. Maybe overdrive the thing and see if I can be harder, better, faster, stronger. Sadly, all of that would likely be painful, so it's just a daydream.
iancmceachern 5y ago
There are people with Heartmate II's (LVADS not artificial hearts, so a bit different) that have lived 10+ years on the devices, with a very high quality of life. That's worth it in my view.

kypro 5y ago

As a layman creating a reliable pump that runs on a battery seems like it would be a fairly easy job for with modern technology. Of course anything mechanical is going to require regular maintenance, but again I wouldn't expect this to be a difficult problem. What are the complications here? Size? Preventing infection? Does it need to adjust flow rate based on oxygen requirements?

jstanley 5y ago
One of the complications is that if it stops working, you don't really have time to fix it before you die.
readams 5y ago
The biggest ones are blood clotting and the mechanical action destroying blood cells.
iancmceachern 5y ago
The challenge isn't in building a reliable pump. The challenge is in the connection between the pump and the human body. If we just put a highly polished titanium tube in the circulation there will be blood clots, hemolysis, and other blood damage. Over time these problems become the main hurdle in getting these types of devices to work.

The_rationalist 5y ago

What improvements and regressions does it have versus the old gen "well established" commercialized artificial heart?

parsecs 5y ago
I'm not sure why this post is flagged and dead. This seem like a genuine and constructive question.
iancmceachern 5y ago
Lots. The old gen, the only approved one, is actually the continuation of the Jarvik 7 made famous by the Barney Clark case. They've been making and using it all this time. It's now called Syncardia. It's pneumatic and the patients have to carry around a bit pneumatic driver that makes quite a bit of noise during every heartbeat. Patients have large air lines running in and out of their chest to carry the air in and out to drive the diaphragm based pump. It works, bit is not ideal in many ways.
- The_rationalist 5y ago
  I didn't knew about the pneumatic and noise annoyance, thanks for sharing

albertTJames 5y ago

How they spin it as a duke achievement is ridiculously vain. They were not the one inventing the tech nor the first to implant it.

korse 5y ago

Does anyone have information about the 'external power supply' of the heart in the linked article? I've found some info that is years out of date and I'm wondering how unobtrusive the unit is now.

iancmceachern 5y ago
Yes, typically they include circuitry/ICs for brushless motor controller to spin the thing, plus a few more "motor" controllers if they have active magnetics for bearings, or other reasons. This needs to all be redundant, or otherwise safe in the mission critical sense. Then they have batteries, and all the stuff that goes with connecting the two (power regulation, conditioning, etc) and alarms, etc.

ed25519FUUU 5y ago

> The Duke patient ... was referred to Duke in June after a sudden, unexpected diagnosis of heart failure. Moore and his wife, Rachel, recently adopted their two-year-old foster son, Marshall, and arrived at Duke expecting only to undergo heart bypass surgery. 39-year-old admitted to the hospital with unexpected heart failure? Is there more to this story? Is this possibly related to the myocarditis being reported with some mRNA reactions?

iancmceachern 5y ago
There are also virus' that attack the heart directly, a few other things that can cause this.

throwitaway1235 5y ago

First artificial heart inventor - https://en.m.wikipedia.org/wiki/Vladimir_Demikhov https://en.m.wikipedia.org/wiki/Vladimir_Demikhov (Albeit non-human)

12bits 5y ago

I just want something like this for my next kidney transplant, I'm so sick of the meds, yes I'm blessed to be alive and living a really good life, but man the 2nd kidney is starting to give me anxiety. Context: Transplant isn't a cure to my autoimmune disease, it will slowly pick away at the graft and have me needing another. Love reading about this kind of stuff.