Here is a little video that we have recorded, of the Medela
Supplemental Nutrition System (Lacta-Aide) actually being
used. There is quite a fine art in positioning the tube just
in the right spot in baby's mouth, so that the suction bring the
milks down the tube. It needs to be right in the hard baby of
the roof of the mouth.
The mum that helped us record this video, says it does take a
lot of patience to get it work correctly. But she says she
can feel when the tube (with supplemental formula) is working,
as she can feel the slightly cooler temperature of the milk on her
nipple as it comes out of the tube.