In the recent times, interacting with machines has become user-friendly. Moreover, the recent innovations in NUIs are making sure that machines can understand human gestures, touch, words, and thoughts in a much better way. Even so, designing for Natural Customer Interfaces is quite challenging as designers have to keep below parameters in mind.

SOUNDS SCI-FI ALTHOUGH TIRING
Minority Report like office sounds really cool, but working with hands upward for a much longer period tire people. URINARY INCONTINENCE should naturally and perfectly interact with the users without tiring them.

natural user cadre

Image Credit rating

CAN'T AFFORD TO DISREGARD THE ACCESSIBILITY
Some signals might not be possible for users with problems. Therefore you can't do away with the support for assistive technology like Joysticks or electronic directed devices.