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Nuclear-Powered Cardiac Pacemakers

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Re: Nuclear-Powered Cardiac Pacemakers

#101

Post by michaelt »

afterburner wrote: post #99
bhaak wrote: post #3

Wonder how I slided into the world of Fallout? WTF!?! We have plutonium powered pacemakers? http://large.stanford.edu/courses/2015/ph241/degraw2/ Ah, okay we had . > Despite the often longer life-expectancies, nuclear pacemakers quickly became a part of the past when lithium batteries were developed. Not only did the technology improve, allowing for lighter, smaller, and programmable pacemakers, but doctors began to…

> Due to the extremely high risk and toxicity involved with using plutonium, numerous layers and shields were woven into these pacemakers resulting in larger and heavier devices. Despite strong concern of radiation exposure, the actual risk of exposure from these plutonium-powered pacemakers was almost non-existent. What a strange phrase. I would say it was because of the concern of the risk of radiation, not "despit…

The claim here is "The risk was tiny due to the superb shielding - but patients were still wary and preferred their implants not have any nuclear material at all"

Re: Nuclear-Powered Cardiac Pacemakers

#102

Post by eloisius »

xtracto wrote: post #39
Bakary wrote: post #17

Tragically relevant story to accompany this article: the Goiânia accident. https://en.wikipedia.org/wiki/Goi%C3%A2nia_accident

Ooh, the Cobalt-60 incident in Mexico is also pretty crazy: https://en.wikipedia.org/wiki/Ciudad_Ju%C3%A1rez_cobalt-60_c... There were houses built of contaminated rebar! The story gets crazier the more you read about it.

This also happened in Taiwan. A metalworks reused Cobalt-60-contaminated rebar and then hundreds of apartment buildings were constructed with it in the 80s. The government tried to find and buy them, but it seems that some people didn’t want to sell because of the amount offered. There are still some of them around.

Re: Nuclear-Powered Cardiac Pacemakers

#103

Post by jerry1979 »

afterburner wrote: post #99
bhaak wrote: post #3

Wonder how I slided into the world of Fallout? WTF!?! We have plutonium powered pacemakers? http://large.stanford.edu/courses/2015/ph241/degraw2/ Ah, okay we had . > Despite the often longer life-expectancies, nuclear pacemakers quickly became a part of the past when lithium batteries were developed. Not only did the technology improve, allowing for lighter, smaller, and programmable pacemakers, but doctors began to…

> Due to the extremely high risk and toxicity involved with using plutonium, numerous layers and shields were woven into these pacemakers resulting in larger and heavier devices. Despite strong concern of radiation exposure, the actual risk of exposure from these plutonium-powered pacemakers was almost non-existent. What a strange phrase. I would say it was because of the concern of the risk of radiation, not "despit…

I think it reads like:

Even though people might worry about radiation from the device, the actual risk (due to all the shielding) is almost non-existent.

Re: Nuclear-Powered Cardiac Pacemakers

#104

Post by sgtnoodle »

furyofantares wrote: post #76
hwillis wrote: post #33

Earlier quoted context omitted.

You really should not. 60 beats per minute means that in ten years the leads of a pacemaker will be bent *315 million* times. That's an order of magnitude higher than we typically test fatigue resistance, and even if we were that confident about being able to produce flawless materials, there are millions of different enzymes and acids and temperature fluctuations in the body. Any one of those could impact the fatigu…

It's a weird argument, though, that we should be checking in on the state of the patient & these devices, but we don't do it unless we have the additional problem of needing to replace a battery.

Modern devices provide a wealth of telemetry completely autonomously. My pacemaker talks at least daily to a UFO shaped brick on my night stand via BLE. The brick has an integrated cell modem, and was given to me pre-configured. It has a bright green light (that turns off in the dark) to show that it's functional. It has a single button I have never pressed, for if I think something notable enough happened that my doctor's office needs to be sent a report sooner than every 90 days or so.

Re: Nuclear-Powered Cardiac Pacemakers

#105

Post by tom_ »

cududa wrote: post #100
nousermane wrote: post #85

Earlier quoted context omitted.

> 315 million times. That's an order of magnitude higher than we typically test fatigue resistance Nah, it's not that bad. Decent mechanical keyboard switch is specified for 100 million clicks [1, or google for "switch million actuations"]. Surely good engineering can eek out another order of magnitude. Not to mention - pacemaker leads ("wires"), the only part that bends, have way less stress on them (= larger bend r…

The absolutely arrogance to assume a keyboard switch and a pace maker are anywhere near the same thing…

Indeed, the keyboard switch people have to produce a device that's manufacturable at scale for pennies per unit, and can be fitted in unforgiving environments by the untrained.

Re: Nuclear-Powered Cardiac Pacemakers

#106

Post by guhidalg »

sgtnoodle wrote: post #98
hwillis wrote: post #33

Earlier quoted context omitted.

You really should not. 60 beats per minute means that in ten years the leads of a pacemaker will be bent *315 million* times. That's an order of magnitude higher than we typically test fatigue resistance, and even if we were that confident about being able to produce flawless materials, there are millions of different enzymes and acids and temperature fluctuations in the body. Any one of those could impact the fatigu…

It sounds like you have quite a bit of knowledge on the subject. I had to get a pacemaker a couple years ago, and am an embedded engineer. I hope to live another 50 years at least, so this is an interesting subject for me. Maybe my cardiologist is just trying to make me feel good, but he says my leads will likely last 30-50 years. Intuitively that seems unlikely, but we'll see. It's got to be one of the most engineer…

My heart sank when you mentioned a BLE-enabled pacemaker. Has technology gone too far? /s

Re: Nuclear-Powered Cardiac Pacemakers

#107

Post by Gordonjcp »

drraj32 wrote: post #5

Just got me thinking: What would it take for us to get to a point where there are small, safe nuclear powered "batteries", that can supply enough electricity for a building.

Far better would be a Pebble Bed Reactor, which more or less fits into a couple of shipping containers and provides a building's worth of power and heat for about ten years with a similar level of maintenance as a diesel genny.

Re: Nuclear-Powered Cardiac Pacemakers

#108

Post by mullen »

OJFord wrote: post #41
tetsusaiga wrote: post #16

I had no idea nuclear power had been miniaturized to this extent, wow.

AIUI there's not really anything to miniaturise beyond the rest of the pacemaker (i.e. ignoring how it's powered) - there's no 'control' or addition of material as in a big nuclear power station, it's 'just' a decaying radioactive material -> heat -> electricity (the inverse of Peltier effect heating, and presumably just as inefficient (~30%?)).

Why not just draw heat from the person and convert it to electricity?

Re: Nuclear-Powered Cardiac Pacemakers

#110

Post by alphaoverlord »

sgtnoodle wrote: post #98
hwillis wrote: post #33

Earlier quoted context omitted.

You really should not. 60 beats per minute means that in ten years the leads of a pacemaker will be bent *315 million* times. That's an order of magnitude higher than we typically test fatigue resistance, and even if we were that confident about being able to produce flawless materials, there are millions of different enzymes and acids and temperature fluctuations in the body. Any one of those could impact the fatigu…

It sounds like you have quite a bit of knowledge on the subject. I had to get a pacemaker a couple years ago, and am an embedded engineer. I hope to live another 50 years at least, so this is an interesting subject for me. Maybe my cardiologist is just trying to make me feel good, but he says my leads will likely last 30-50 years. Intuitively that seems unlikely, but we'll see. It's got to be one of the most engineer…

If you have complete AV block, a leadless pacemaker is less good than one with multiple leads, since it allows pacing multiple chambers and maintaining synchrony between A and V.
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