4 ms·

The pacemaker or ICD generator is replaced when the battery is exhausted, typically 8–10 years. The procedure is not a big deal, it is commonly outpatient and

by etendue 10y ago

The pacemaker or ICD generator is replaced when the battery is exhausted, typically 8–10 years. The procedure is not a big deal, it is commonly outpatient and done under local. Outside of some durable orthopedic implants, few implants will survive in the body for 50 years: it is a very hostile environment.

abandonliberty 10y ago
>it is a very hostile environment. I've never thought of it this way, and you are right from both a technological and biological perspective. Biologically we are wonderful containers of nutrients, but we have an army only the very sneaky or militant can overcome. Once that army stands down we are rapidly colonized - which is why we must be so careful with food/meat storage.
- Apofis 10y ago
  You just made me realize why bacteria and other things want to kill us so badly... we are precisely that, really extremely-high concentration stores of nutrients.
3chelon 10y ago
Useful to know. Of course, batteries get better and electronics gets lower powered - I can imagine in the near future implanted devices being effectively passive (such as RFID)... but your point about the body being a hostile environment is definitely something I hadn't considered before.
- etendue 10y ago
  To expand on one aspect of hostile, some white blood cells greet foreign bodies with micromolar concentrations of a variety of oxidants and radicals: hypohalous acids (not just the familiar household bleach, hypochlorous acid, but also the nastier hypobromous acid), peroxides, superoxide, nitroxides, maybe even hydroxyl radical. Realizing that, it's easy to see why autoimmune diseases are so devastating.
  - 3chelon 10y ago
    Of course, it's chemical warfare down there. Using strong acids and the like to destroy bacteria and virus structures is something I'd heard about, at the microscopic level, but I'd absolutely never thought about its implications on a macro scale before. Presumably they sheath these devices in inert plastics or something in an attempt to counteract all this?
    - Balgair 10y ago
      We do. Silicone, gold, porcelain, and titanium are actually pretty good for being bio-inert as well as many many other compounds. The metals obviously come with many issues too (heav metal poisoning, weight, different elasticity, etc) and the plastics are not as durable or tough as the metals. Also, these things tend not to be 'squishy' so impacts and wear and tear are tough on them. Fun fact: Gold teeth caps are really good for you, though maybe not your love life. Gold has very very similar mechanical parameters to your dentin. Overall, bioengineers are making great strides into these compounds. We are developing new heart stents that coil and expand in response to heat or can just be injected and will solidify and expand wherever they are needed. A cool development sector is in 'smart' hip replacements. They have nano-pores in the titanium to induce bone growth into the implant and create a better and more healthy bond.

by etendue 10y ago

abandonliberty 10y ago

>it is a very hostile environment. I've never thought of it this way, and you are right from both a technological and biological perspective. Biologically we are wonderful containers of nutrients, but we have an army only the very sneaky or militant can overcome. Once that army stands down we are rapidly colonized - which is why we must be so careful with food/meat storage.

Apofis 10y ago
You just made me realize why bacteria and other things want to kill us so badly... we are precisely that, really extremely-high concentration stores of nutrients.

3chelon 10y ago

Useful to know. Of course, batteries get better and electronics gets lower powered - I can imagine in the near future implanted devices being effectively passive (such as RFID)... but your point about the body being a hostile environment is definitely something I hadn't considered before.

etendue 10y ago
To expand on one aspect of hostile, some white blood cells greet foreign bodies with micromolar concentrations of a variety of oxidants and radicals: hypohalous acids (not just the familiar household bleach, hypochlorous acid, but also the nastier hypobromous acid), peroxides, superoxide, nitroxides, maybe even hydroxyl radical. Realizing that, it's easy to see why autoimmune diseases are so devastating.
- 3chelon 10y ago
  Of course, it's chemical warfare down there. Using strong acids and the like to destroy bacteria and virus structures is something I'd heard about, at the microscopic level, but I'd absolutely never thought about its implications on a macro scale before. Presumably they sheath these devices in inert plastics or something in an attempt to counteract all this?
  - Balgair 10y ago
    We do. Silicone, gold, porcelain, and titanium are actually pretty good for being bio-inert as well as many many other compounds. The metals obviously come with many issues too (heav metal poisoning, weight, different elasticity, etc) and the plastics are not as durable or tough as the metals. Also, these things tend not to be 'squishy' so impacts and wear and tear are tough on them. Fun fact: Gold teeth caps are really good for you, though maybe not your love life. Gold has very very similar mechanical parameters to your dentin. Overall, bioengineers are making great strides into these compounds. We are developing new heart stents that coil and expand in response to heat or can just be injected and will solidify and expand wherever they are needed. A cool development sector is in 'smart' hip replacements. They have nano-pores in the titanium to induce bone growth into the implant and create a better and more healthy bond.