3 ms·

> That being said, 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 mech

> That being said, 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 is this? What are the downsides of just keeping this artificial heart forever? Do the components somehow wear out so fast that it makes more sense to have another surgery with a real heart, or is it something with the recharge requirements, or something else?

Filligree 2y ago
For one thing there’s no pulse. The human body is very much designed assuming one.
- drakonka 2y ago
  I hadn't considered that. What are some practical implications for living without a pulse?
  - gosub100 2y ago
    having your feelings hurt when people use the phrase "anyone with a pulse"
    - psunavy03 2y ago
      At which point you say "I DON'T have a pulse and even I know X . . ."
  - Filligree 2y ago
    It’s hard to say for sure; we don’t have enough people doing it. But just for one… your arteries contain one-way valves and smaller pumps, to keep blood from pooling in your legs, or from failing to reach your head. These aren’t absolutely critical—children don’t die while standing on their heads—but I can’t imagine they’ll work quite as intended without pulses. You can’t just swap the main pump on a massive hydraulic system for a different design, and not expect something to go wrong.
- graybeardhacker 2y ago
  There are blood pumps which recreate pulse. The BiVACOR does not. The Abiocor, first implanted in July 2, 2001, does have a pulse.
Cthulhu_ 2y ago
The problem with an artificial heart is that if it dies, you die; a real heart is (I am confident) more reliable and will have more warning signs and partial functionality before quitting. For now anyway, I'm confident that in our lifetime artificial hearts and whatnot will become more reliable.
- drakonka 2y ago
  I hadn't thought of that, that makes sense! I wonder if we can one day have artificial hearts with a built-in warning system for failure. Maybe they could even flag irregularities _before_ total failure and go into some kind of minimum maintenance mode, giving the user time to get to a hospital in (relative?) comfort. Edit: sorry, I realized you suggested almost this exact thing above; I just got excited and replied too fast.
teddyh 2y ago
“He wants metal; they always do.” — Segregationist, Isaac Asimov, 1967: <https://archive.org/details/Fantasy_Science_Fiction_v035n04_1968-10_PDF/Fantasy__Science_Fiction_v035n04_1968-10_PDF?view=theater#page/n77/mode/2up https://archive.org/details/Fantasy_Science_Fiction_v035n04_...>
graybeardhacker 2y ago
All heart pumps damage the blood. So far we've not found a way to pump blood without causing damage due to various factors, sheer, pressure, heat, etc. Impellers are particularly bad. Alternatives that use flexible membranes are better but still not perfect. Abiomed and Ventriflo both had pumps that use a flexible membrane. Abiomed had the first TAH (total artificial heart) to be implanted. There are also other problems with blood pumps, such as stasis areas where blood can stagnate causing issues like thrombosis. These can be caused by valves or other issues in the flow path. People on blood pumps need blood thinners and anticoagulants which can cause their own problems long term. Source: 15 years of working on blood pumps.
- drakonka 2y ago
  Thank you for the insight!

Filligree 2y ago

For one thing there’s no pulse. The human body is very much designed assuming one.

drakonka 2y ago
I hadn't considered that. What are some practical implications for living without a pulse?
- gosub100 2y ago
  having your feelings hurt when people use the phrase "anyone with a pulse"
  - psunavy03 2y ago
    At which point you say "I DON'T have a pulse and even I know X . . ."
- Filligree 2y ago
  It’s hard to say for sure; we don’t have enough people doing it. But just for one… your arteries contain one-way valves and smaller pumps, to keep blood from pooling in your legs, or from failing to reach your head. These aren’t absolutely critical—children don’t die while standing on their heads—but I can’t imagine they’ll work quite as intended without pulses. You can’t just swap the main pump on a massive hydraulic system for a different design, and not expect something to go wrong.
graybeardhacker 2y ago
There are blood pumps which recreate pulse. The BiVACOR does not. The Abiocor, first implanted in July 2, 2001, does have a pulse.

Cthulhu_ 2y ago

The problem with an artificial heart is that if it dies, you die; a real heart is (I am confident) more reliable and will have more warning signs and partial functionality before quitting. For now anyway, I'm confident that in our lifetime artificial hearts and whatnot will become more reliable.

drakonka 2y ago
I hadn't thought of that, that makes sense! I wonder if we can one day have artificial hearts with a built-in warning system for failure. Maybe they could even flag irregularities _before_ total failure and go into some kind of minimum maintenance mode, giving the user time to get to a hospital in (relative?) comfort. Edit: sorry, I realized you suggested almost this exact thing above; I just got excited and replied too fast.

teddyh 2y ago

“He wants metal; they always do.” — Segregationist, Isaac Asimov, 1967: <https://archive.org/details/Fantasy_Science_Fiction_v035n04_1968-10_PDF/Fantasy__Science_Fiction_v035n04_1968-10_PDF?view=theater#page/n77/mode/2up https://archive.org/details/Fantasy_Science_Fiction_v035n04_...>

graybeardhacker 2y ago

All heart pumps damage the blood. So far we've not found a way to pump blood without causing damage due to various factors, sheer, pressure, heat, etc. Impellers are particularly bad. Alternatives that use flexible membranes are better but still not perfect. Abiomed and Ventriflo both had pumps that use a flexible membrane. Abiomed had the first TAH (total artificial heart) to be implanted. There are also other problems with blood pumps, such as stasis areas where blood can stagnate causing issues like thrombosis. These can be caused by valves or other issues in the flow path. People on blood pumps need blood thinners and anticoagulants which can cause their own problems long term. Source: 15 years of working on blood pumps.

drakonka 2y ago
Thank you for the insight!