This is certainly cool and I love my Craftbot 3d printer. However, one has to mention the problems with using 3d printed devices like this. This is not to tear apart the project, but I would hope valid criticism. Medical gear like this is commodity stuff that is actually very inexpensive. I do think 3D printing will democratize the really expensive medical equipment, but we are not there yet.

#1 cleanability - It is very hard to properly clean a 3d printed item and each print may be a little different than the others.

#2 Cost - For the same cost, I can buy a stethoscope on Aliexpress that is made from aluminum and pvc. For about $5 I can purchase an actual Littmann replica made from the same durable parts as the previously mentioned steth from Aliexpress. The same goes for all of the designed products they have.

#3 Durability - PETG and ABS are relatively durable, but they do not compare to aluminum in terms of strength. In emergent situations, I would not trust plastic for my gear. In the clinical setting, I can see the use case, but still like the term "buy once, cry once" when it comes to tools that will see lots of use.