The patent
ASLEEP MASK ® Travel Sleep Mask | Innovative patented device patent no. WO 2014203055 A1
Weightlessness of the head during sleep in a seated position
![masque de voyage masque de sommeil voyage masque yeux avion asleepmask brevet](http://asleepmask.com/cdn/shop/files/masque_de_voyage_masque_de_sommeil_voyage_masque_yeux_avion_asleepmask_brevet_2_liens.png?v=1707728652&width=1500)
The patent sentence says
"It is a device allowing the head to be maintained in an anatomical position thanks to the links (head and seat) [...].
This device supports the head in an ideal postural attitude from the first cervical to the last lumbar (in almost weightlessness)."
In these conditions, there is no possibility of head play.
It is in perfect balance, in the vertebral axis, it weighs nothing!
This results in a feeling of weightlessness in the head!
(For information, Head weight: 7 kg on fascia)