Considerations for using surplus medical implant magnets?

So say you got your hands on some cochlear implant magnets and are considering placing at least one of them somewhere in the hand/forearm area.

Three are solid titanium coated disc-shaped magnets:
(1) 1.4g 11.95x2.2mm
(2) 1.6g 10.9x2.5mm

These seem pretty straight forward, I’m wondering what placement considerations should be made regarding their size.

Two are a little funky; they have a hole through the center with a max 1mm (probably closer to 0.5mm) flange on one side which allows for a titanium screw to fit inside.

(2) 7g 27x2.4mm

They’ve got a small hole through the middle and a flange, how much does one think this flange would affect viability as an implant in the forearm, and how real is the risk for biofilm formation with these additional edges? Having a jeweler file down the flange could make a more uniform shape, but this adds the factors of potential metal shavings on the device and altered surface topography, the latter bringing us back to the risk of biofilms.

Am I overthinking this? Leaving anything out? Crazy for even considering it? Curious what others think.

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Pictures would help a lot. If these are implant grade already and you want to avoid biofouling, I wouldn’t modify them at all. They’re likely extremely polished. Having a hole in the center doesn’t have a very noticeable effect on the field strength, that’s why they were able to remove it to reduce weight.

I don’t think you’re overthinking it. The only thing I’d be worried about is if there are inside teeth on the screw hole. If there are and you’re not putting a screw in there in your application, then there are some risks of biofouling

Here are a few pictures. I’m wondering how much the flange would affect comfort.

hmm that seems like it would be very uncomfortable. Is the intended install after a hole has been drilled in the skill to accommodate that flange, or does the flange stick outward and is shrouded by the screw head?

The flange seats into another device placed into the skull and accommodates the screw head. This is an earlier model, the other magnets are simply discs that slide into a silicone pocket. Makes things easier for when someone needs to get them removed for an MRI.

Speaking of mris, there is official data online that explains these magnets are safe for MRIs up to a certain strength.

Anyway, I’m leaning towards the idea of filing that piece down.

If it’s all titanium, just have that bit machined flat. Should be no harm in that. You just want to be sure you don’t breach the shell and expose the magnet part.