So after inspiration form the likes of Neon22 (now a collaborator) I have had another shot at a more printable version in the CPAP prongs. But have hit a snag.
So this is the new version - just the centre of the device coded at this stage - this will sit below the nose. The flat surface will sit against the face (wider distribution of load) and eventually the side 'arms' will curve to follow the infants face. This looks ok - but before I got carried away I exported it using nervous system's Processing library (exports an .obj file I can open in slicing software). This is my problem - the obj exporting library doesn't support the beginContour/endContour method I have used to 'cut out' the holes where the nares tubes intersect the top surface. So this whole top surface disappears when exported. Damn.
So more code needed - I should be able to solve this by drawing half the surface at a time - easy to fix - just will take some more lines of code. Once this is fixed I need to do some test prints - This design will still have some unsupported overhangs (2-3mm) so I'll need to see how they print and maybe modify further.