Diameter and center line of 3D stomach realization ?

Hi everyone,

The output I'm trying to reach is reading a 3D model of a stomach, get the centre line of it and fit it with a curve, then find the diameter (outer shape) of the stomach at a certain point on the fitted curve.

So, I managed to get the 3D skeletonized centre line by Skeleton3D, clean it from extra branches by deleting the extra points, rotate the line in order to be able to fit it with a polynomial equation.

From the curve I got (the polynomial equation), I would like to get the diameter of the stomach outer shape (approximately as the curve differ from the original centre line) so I can draw perpendicular line presenting that diameter, therefore, I could build a stomach that would be analysed by the centre line and the diameter in 3d space.

I'm not sure what I'm doing is on the right track or I should do something else from beginning.

Hope I was clear and thank you :)