Outside of the brain, the heart is probably the organ that you miss the most when it ceases to function correctly. Unfortunately, as we cannot grow custom replacement hearts yet, we have to keep heart patients alive long enough for them to receive a donor heart. Yet despite the heart being essentially a blood pump, engineering even a short-term artificial replacement has been a struggle for many decades. A new contender has now arrived in the BiVACOR TAH (total artificial heart), which just had the first prototype implanted in a human patient.
Unlike the typical membrane-based pumps, the BiVACOR TAH is a rotary pump that uses an impeller-based design with magnetic levitation replacing bearings and theoretically minimizing damage to the blood. This design should also mean a significant flowrate, enough even for an exercising adult. Naturally, this TAH is only being tested as a bridge-to-transplant solution, for patients with a failing heart who do not qualify for a ventricular assist device. This may give more heart patients a chance to that donor heart transplant, even if a TAH as a destination therapy could save so many more lives.
The harsh reality is that the number of donor hearts decreases each year while demand increases, leading to unconventional approaches like xenotransplantation using specially bred pigs as donor, as well as therapeutic cloning to grow a new heart from the patient’s own cells. Having a universal TAH that could be left in-place (destination therapy) for decades would offer a solid option next to the latter, but remains elusive. As shown by e.g. the lack of progress with a TAH like the ReinHeart despite a promising 2014 paper in a bovine model.
Hopefully before long we’ll figure out a reliable way to fix this ‘just a blood pump’ in our bodies, regardless of whether it’s a biological or mechanical solution.
This is cool but it reminds me how much I want them to make artificial joints that don’t try to 1:1 copy natural joints. Artificial knees still use a metal ball on a plastic disk, from what I understand, wear out quicker than I’d like and rely on healthy ligaments to hold things together.
How much cooler would it be if they just went all in with proper bearings and maybe some shocks? I want something that doesn’t try to copy the joint but goes beyond and acts like a part engineered to last forever.
For every amazing piece of technology which looks like magic, there is another equally amazing piece of technology which seems very primitive (to me, a non-subject expert)
All we can hope is they did their due diligence and it was designed by engineers, not doctors
This is a pretty fair take. My comment is born out of my desire that your last point is being followed (at least to some degree, doctors need to be heavily involved too), but another is having seen the damage that people can suffer when their ligaments go alongside the joint.
Seeing all the joint replacements for them not have any way of compensating for bad ligaments is a tad bit frustrating because it means at least a good chunk of the problems can recur when they loosen after surgery.
Ligaments holding the knee together is good. Youd much rather a torn ligament than a broken bone. Especially if youre talking about the bone breaking because of the leverage applied to an threaded shaft embedded in it.
Metal on Metal and Ceramic on Ceramic Knee implants exist and last longer than plastic on metal but each has its own drawbacks and complications.
All knee implants have proper bearing surfaces. Are you seriously advocating the implantation of ball/pin bearing systems? You do understand those all wear out too?
Ligaments holding a joint together is all well and good. Unless you have are hyperflexible or have a history of ligament injuries. Then they might not really be holding the joint together.
I did suggest adding some sort of shock absorption in if they were to remove the ability for the joint to slip and slide, or pull apart. I can understand that much of the benefit of having flexible stretchy ligaments holding a joint together instead of a rigidly attached joint.
I would never suggest a ball or pin bearing, especially since those are designed for high speed light weight joints typically. However, I may not be above the idea of a big roller bearing. Something that could easily last more than a decade in machinery far heavier than a person.
Metal on Metal implants would definitely be closer to what I’d hope for (many joints are themselves very solid bearings). I honestly hadn’t seen them before because of how much Metal-on-Plastic is emphasized.
Really the comment is an expression that I hope that they are very much considering it as an engineering problem and not just a medical one. Duplicating form is well and good since evolution is very good at optimization, but there are things it can’t explore and places where technology could be an improvement.
Your body is built around a specific method of functioning. This idea is akin to saying “I want 2+2 to equal potato,” sure you could do that if you modify all mathematics, and modify it correctly.
Same with completely changing a joint/muscle/tendons/feedback mechanisms in skin and brain
This comment is plain meaningless.
“2+2=potato” is weird and arbitrary but you can absolutely just name a variable potato and be on with it without upending mathematics.
Even in the most extreme case this isn’t something so extravagant that would completely mess with someone’s basic control of their body.
Guys like you are funny, always think you know better. I cant say much, I did as well 10 years ago with my classic car.
I decided to upgrade the engine with a full rebuild to handle more power, bore, sleeves, cam, JE Pistons, ARP headstuds, etc.
Power gain was about 50hp and a minimal amount more torque. Nothing crazy.
Oh look because of that the power band has holes and the fuel system needs to flow more.
Fuel rails, and crank trigger ignition and there are still things breaking.
Frankly you are obtuse and obviously not a doctor if you think a redesign wont have unintended consequences and issues.
If knee replacements were built like car bearings, your knees would only last 200 days before needing a replacement.
(Front end bearings last 100k miles which is 1667 hours of driving.)
I suspect our current implants are mostly intended to work as drop-in replacements, to do something more ambitious would amount to a full amputation and robo-limb. That might get some takers, but it’s a pretty drastic “upgrade”.
Billion dollar medical manufacturer doing clinical trials of a device they spent millions developing…..hack? NAH
Not a hack, but still the kind of thing I’m interested in and don’t see covered elsewhere. More quality content is always welcome.
Shhh
I wonder what its power draw/battery life is…
Being a prototype, power draw isn’t a detail in their press kit information.
“Battery life” specifically is somewhat irrelevant, as the batteries are external and replicable. If you meant charge time, even that is technically adjustable just by using different capacity batteries.
For comparison the Abiocor TAH has an internal battery pack that lasts 4 hours plus a wireless charger pad under the skin for use with an additional external battery pack (4-6hrs per pack) as well as its power transfer “belt” for tethered power. This is almost a 20 year old “mature” device.
There’s no reason this new device couldn’t use the same power delivery system as other existing devices.
Once the internal battery takes over,
you got one f**king hour.
.
.
I’m in need of an external lithium
battery belt for an Avicor Total Artificial Heart.
“Congratulations sir…you have just received the new Tesla Artificial Heart with its super battery. You will have the freedom to go anywhere you want……well…with the minor exceptions of finding a super charger, needing 12 hours to recharge, software updates and the possibility of bursting into flames…but hey… you’re gonna be just fine.
In her award-winning short story Aztecs, Vonda McIntyre had space pilots hearts removed (hence the story title) and replaced with rotary pumps to eliminate any rhythms that would disturb the pilot in FTL travel. Silly idea, but compelling story.
Today’s fighter pilots might benefit from an artificial heart that can go into “scramble boost” mode for high-G maneuvering. Although they might benefit even more from having prosthetic legs that blood can’t pool inside. Long-range missiles and autonomous drone wingmen will keep fighter pilots safe from all kinds of wacky ideas like these :-P
In Star Trek The Next Generation….Picard has an artificial heart. Also in Space 1999 Dr. Bergman has one but his has a wristwatch like device for adjusting it.
In Robocop (1987) there’s a mock tv commercial for the Family Heart Center selling artificial heart replacements. It was in the style of a car dealership ad complete with a spread of models, financing, and disclaimers.
It seemed absurd and dystopian in the ’80s that life saving equipment could be sold like a luxury good, but I don’t think anyone would be shocked if a modernized version aired today.
“and remember, we care.” :)
Some context.
I’ve dealt with all manner of artificial and augmented heart tech for the longer than I’d like to admit.
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The engineering challenges are many, probably the very least of which is things like battery life, etc. even rejection or host-graft interactions are mostly solved
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The real challenges are making a mechanical pump that doesn’t shred your red blood cells or platelets. Human blood is a very complex fluid that does many non-intuitive things. Carries oxygen are but also takes away co2, metabolic byproducts, and literally interacts with every tissue in the body’s (with few rare exceptions). Shreded red blood cells can release bad things that relatively quickly wreck your kidneys that you also need to, well, live. One example. Plus that same device also has to have about zero dead zones of stasis or else you get clots that go to unfortunate places like your brain and cause strokes or big clots to the lungs causing a bunch of other bad things. So to get around this you can anticoagulate which also has a bunch of risks
Finally a not well understood point is that your heart beats and pumps blood (clearly) but many of those devices are laminar flow or continuous flow pumps. Turns out for lungs and some other things, especially endothelial tissue (the lining of blood vessels) the pulsation flow can be important for other subtle reasons.
The other problem is variable speed/heart rate and variable pressure. Biological heart adjusts to the needs of the body. This also can lead to blood pressure going too high due to bad diet, too much weight, stress and other factors. Artificial heart could limit that, but OTOH it still needs wide range of operation…
Well said, which is why I think the future will lie in xenotransplantation in the short term and “regrown” hearts in the long term.
Thanks for the explanation.
Why not just make it external, worst case it could be pumped by patient.
Already exists and is in widespread use. The ones I’m most familiar with are referred to as a “VAD” (ventricular assist device) and have an implanted pump (not a total replacement heart) with a drive wire that exits the skin to the motor itself and power unit. The drive wire looks like and basically is a bicycle brake cable. The patient wears a pack slung over the shoulder with batteries for going out and about. If I recall, the batteries last about 4 hours. Of course, there are alarms, timers, etc. A major component of receiving such a device is the training on how to manage it.
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one of the more fascinating things about VADs is that they used to mostly be thought of as “bridge to transplant” but occasionally that wasn’t an option so it was used as “destination therapy” i.e. when it goes, you go. we were seeing many people greatly exceed their expected duration. Turns out, if your heart is failing (a huge heterogenous group of pathologies) and you rest it or unload some of its work, it can actually repair and heal sometimes, to some extent. Best analogy I’ve heard is if you are riding a donkey, and the donkey gets tired, you can either beat it harder to make it keep going, or get off and walk and let the donkey rest.