Cancer patient gets a 3D-printed titanium rib cage | Hacker News Reader

Cancer patient gets a 3D-printed titanium rib cage

csironewsblog.com

44 pointsPamar14 comments

This is one of those situations in which incremental improvements in technology add up enough that they enable some pretty amazing applications. Very cool.

Aside from the 3d printing, this is possible largely because of huge advancements in immune-inert implantable materials and anti-biofouling coatings. I think we're ready to see this sort of thing become the norm very very quickly.

Material science is behind lots of advances in the `cooler' technologies. (And better numerics are behind lots of advances in the `cooler' parts of computing.)

Lately it seems like I've run into a lot people interested in the so-called materials genome:

https://www.whitehouse.gov/mgi

I'm curious why they needed to use additive manufacturing instead of machining and joining the parts.

Additive manufacturing allows for better bonding then machining and joining the parts. Its essentially molecular welding, depending on whether you're doing SLS (sintering) or SLM (melting).

I don't understand though why the rib replacements are so thin. it seems dangerous to have a lot of soft tissue around such thin and hard metal bars.

I would assume that titanium has a higher density than bone and rib bones aren't that large to begin with. Making them larger and thereby heavier would probably cause a few problems.

It may also be for the purpose of simulating to some degree the flexibility of the ribs at each level.

Titanium 4.5g/cubic cm versus human bone at 1.85g/cubic cm.

You could make the titanium parts hollow. That would solve the density problem.

3d printing with metals allows for much more complicated geometries but it's not magic, there are still significant limitations, doubly so when you're talking about implants.

For example, there would have to be perforations for extracting the raw material from inside the hollow interior (probably titanium powder in this case) which means that you now have a hard to post process implant (titanium isn't exactly bioinert) with an exponentially greater surface area for possible autoimmune reactions or infections and an interior that is probably damn near impossible to sterilize (since you'd probably honeycomb the walls).

Question directed to people in the 3D printing scene: What undiscovered uses for 3D printing do you think can really help?

"That's so cool. I look like freakin' Wolverine!" --Dave Lizewski, Kick-Ass

Url changed from http://www.engadget.com/2015/09/11/spanish-cancer-patient-ge..., which points to a gizmodo.com article which points to this.

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