3 ms·

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 devi

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.
marcan_42 5y ago
A heart uses nowhere near 100W of power. That's about the overall power consumption of the entire human body at rest.
- aetherspawn 5y ago
  My estimation was based on a value that is a fraction of the smallest brushless automotive water pump that I work with, which is smaller than a heart and barely suits a go kart.

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.

marcan_42 5y ago

A heart uses nowhere near 100W of power. That's about the overall power consumption of the entire human body at rest.

aetherspawn 5y ago
My estimation was based on a value that is a fraction of the smallest brushless automotive water pump that I work with, which is smaller than a heart and barely suits a go kart.