Kwang Hyun Jang : modulation slider

A recent patent from Korea (WO2011/007978). Filed July 6, 2010 and registered January 20, 2011, this patent by Kwang Hyun Jang, Seoul, Korea, exposes a "Nose Flute Instrument Capable Of Modulating The Tone Thereof".

Mr Jang invented a slider system, which allows the operator to "modulate the tone" of the produced sound.

« Disclosed is a nose pipe instrument capable of modulating the tone thereof. The
nose pipe instrument capable of modulating the tone thereof enables a
modulating plate to slide to adjust the length of a sealing path for the passage of
breath from the nose of a player. Thus, the nose pipe instrument of the present
invention can modulate the pitch of the tone to be played, thereby enabling
various notes to be played. »

In Korean, for amateurs :

I have to admit I am not sure to fully understand the exact purpose of the device. If it is intended to be slided during the play, it's a nonsense regarding "bucal cavity driven" nose flutes... or will it produce a "special effect" ? A double pitch ? I doubt of that, but I may be wrong.
More likely it is featuring in order to "set" the flute before playing, in sharp or bass mode.