Fairly straightforward. I'm writing a character with a regenerative ability that's prone producing cancerous tumors when healing from substantial injury. A friend suggested having some sort of biocomputer implant be introduced to manage it, but I'm not sure where in the body to put the darn thing.

Without getting into details about how the power-set works, power and noise aren't issues here, and it's expected to run autonomously for the most part. I can't find what the expected size of a working, practical biocomputer would be (best I found is one the size of a book), so I'm hand-waiving it a bit to be the size of a capsule.

Is there an area inside the body that's relatively problem free to put this at? And as a bonus, what problems can be expected from putting such biomass at one place in the body compared to another (assuming there's not an optimal location)?

Edit: Preferably somewhere besides a limb, because the removal of that limb would hamper the ability to control the regeneration of so much biomass.

  • $\begingroup$ What is the size of a capsule? (To me that sounds like a couple centimeters or less) $\endgroup$ Sep 17, 2020 at 17:26
  • $\begingroup$ Looks to be between 1 and 3 centimeters, so you're right on the money $\endgroup$ Sep 17, 2020 at 17:30
  • $\begingroup$ does the implant need to be hidden? otherwise just about anywhere can work there will just be a bump under the skin at its location unless placed deeper. Does the implant need access to certain conditions or organs to work? Great first question thus far. Try checking out the Tour and Help Center $\endgroup$
    – IT Alex
    Sep 17, 2020 at 18:21
  • $\begingroup$ @ITAlex Thanks! I should have included that in the OP. Yes, preferably the implant would not be on a limb and not have an obvious location, as then the loss of the implanted limb in combat would remove controlled healing of the user. $\endgroup$ Sep 17, 2020 at 18:34
  • $\begingroup$ Humans recurrently carry heavy, linked but independent objects inside their bodies. I wager your capsule weights less than 3 kg. So it's feasible although possibly uncomfortable. Ask any woman who carried a child. $\endgroup$ Sep 18, 2020 at 17:14

3 Answers 3


You want to place it adjacent to the brain, preferably right under the thalamus where it's least likely to get damaged by anything that does not need to go through your brain to get to it.

The reason is that every part of your body can be restored to its original state through adequate regeneration abilities except for the brain. The brain contains a lot of information that is not stored in your body's genetics so if you get brained, then you are dead whether your body can heal from it or not; so, there is not much reason to care if you can repair your body if your brain gets wiped. Anywhere else and you risk "the you that is you" surviving, but your bodying failing at regenerating itself.

While this may seem like a dangerous place to put it, your subject has inhuman regeneration; so, the trauma of surgery is not a very big concern. Just go in through the nasal cavity or roof of the mouth to insert it. There is a relatively open cavity filled with Cerebrospinal fluid right there with enough room for a pill sized implant to not interfere with the function of the brain. Also, this part of the brain is responsible for primitive functions that you are born knowning how to do; so, if this part of the brain gets nicked in the process, then your regeneration can restore you to your full functionality VS higher in the brain where you would suffer memory loss.

enter image description here

That said, perhaps your bio computer has the ability to backup your memories to it, then you could be decapitated, grow a new head, and restore your memories from the biocomputer. In this case, the best option would be to use multiple redundant implants such that you have several throughout your body. That way if part of you gets taken out along with several implants, you still have a few spares.

That said, you still have to be a bit careful with yourself in this case because if you get cut in half you might wind up with a duplicate you running around who might not be too keen to share his home/wife/kids/job/finances/etc with you.

enter image description here

  • $\begingroup$ I had considered the brain for some of those reasons, but I wasn't sure it could work. Now that you point it, having regen does make this less of any issue. 😅 Thanks! $\endgroup$ Sep 17, 2020 at 23:13
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    $\begingroup$ I would also add that the fluid surrounding the brain is rich in glucose, and that the computer might be powered from that glucose using a small fuel cell. $\endgroup$
    – user4574
    Sep 18, 2020 at 2:33
  • $\begingroup$ Shades of Total Recall.... $\endgroup$
    – CGCampbell
    Sep 18, 2020 at 13:29
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    $\begingroup$ @user3067860 At the size of a capsule, you should be fine. Your brain floats in a layer of Cerebral spinal fluid that is several mm thick in many areas.... or you could go just a bit lower an implant it in the sinus cavity. $\endgroup$
    – Nosajimiki
    Sep 18, 2020 at 16:00
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    $\begingroup$ I missed the last paragraph at first, but I think that could be a very important thing to consider in this case - and with the ability in general - clones without your memories but with your abilities may be even more dangerous $\endgroup$
    – TCooper
    Sep 18, 2020 at 22:40

Upper Arm.

enter image description here

This is where current tech implants go, eg hormonal or contraceptive. One of the main advantages of this location is it can be accessed quickly, and with only local anesthetic.

In the event of malfunction it can be removed in minutes.

  • 3
    $\begingroup$ +1 for thinking of a way to make the implant accessible. I had overlooked that. $\endgroup$ Sep 17, 2020 at 18:58
  • $\begingroup$ Ahh, a very good point! $\endgroup$ Sep 17, 2020 at 19:13
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    $\begingroup$ Add a spare in the other arm. $\endgroup$ Sep 18, 2020 at 7:08

If you want the user to regenerate any body part, you want this implant in a place where it has access to major blood vessels. You also don't want this to interfere too much with anything vital.

The abdominal cavity is a place to consider. There is plenty of usable space in it. When you get a transplant kidney, for example, doctors find some space for it around the small intestine. And in women, that is where the womb expands into when a baby is forming.

A 1-3 cm implant will be as big as a fetus that is around 8 and 10 weeks old. At this stage a pregnant woman should start feeling some tightness in the belly, but only around the 11 and 12th weeks the belly begins to really grow noticeably.

As a plus, if you place it close to the liver you'll have access to the inferior vena cava, one of the largest and most important veins in the body. When you open the wiki in the link, look at the diagram of the heart - it's the vein comin in from the lower left corner. It takes the output of the liver straight to the heart, it's the perfect place to deliver whatever the implant needs to deliver.

  • $\begingroup$ Great suggestion and explanation! If I don't see a better one by tomorrow, this will likely be the accepted answer. $\endgroup$ Sep 17, 2020 at 18:36
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    $\begingroup$ put it right up against the spine or pelvis and it will have pretty good protection as well as maintaining the same vessel access. plus it gives you pretty good nervous access. $\endgroup$
    – John
    Sep 17, 2020 at 21:29
  • $\begingroup$ Pelvis gives you something to anchor to, as well, you don't want it wandering around the body. $\endgroup$ Sep 18, 2020 at 14:31
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    $\begingroup$ This is approximately where real implants go today when you can pick where to put them. e.g. universityhealthnews.com/wp-content/uploads/… is a pacemaker. Some of the electronics need to go right by the heart. all the auxiliary stuff lives in another box in the abdomen. $\endgroup$
    – fectin
    Sep 18, 2020 at 15:21

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