FullDive

FullDive is the use of technology to fully immerse one's conscience in virtual reality. Developed by Kayaba Akihiko it led to the creation of the device called NerveGear. It is the basis of most of the stories in the series. A NERve Direct Linkage Environment System or NERDLES (ニードルス) is required for a FullDive.

Known VR Consoles

 * NerveGear
 * AmuSphere
 * Medicuboid
 * Soul Translator

Nerve Gear
The NerveGear (ナーヴギア) was created by Argus. It completely controls player's consciousness by redirecting the signals the brain sends to the body and sending it's own waves to stimulate the five senses. It has its own battery source, as well as a high frequency electromagnetic microwaves emisor. Nerve Gear, when first produced, only puzzles, education related, or environmental type games were brought out. So, Sword Art Online was a major excitement to the gamers. This design trapped 10,000 players during the official launch of Sword Art Online. It's the first VR technology that has been mass-produced.

AmuSphere
AmuSphere (アミュスフィア) is the revised version of the NerveGear which was developed by [http://swordartonline.wikia.com/wiki/RECTO_Progress_Inc. RECTO Progress Inc.]. The system has been modified to make it safer than it's predecesor by changing the microwaves emisor to a low frequency one and the incorporation of various sensors that continually monitor blood pressure and brain waves which provoke a safety logout feature in case that the person's statuses become abnormal.

Medicuboid
Medicuboid (メディキュボイド) belongs to the same generation as the AmuSphere, but it was developed by the government research. It's above the AmuSphere because it's composed by a complete bed, rather than just a helmet; it connects not only to the medula, but to the spinal cord also, besides possess a greater processing power allowing an interaction with deeper parts of the brain. All this improvements provide the user with enhaced reflexes and reaction time. However, this helmet is used specifically for medical purposes, specifically for pacients in Terminal Care. The users of Medicuboid hardly uses their own body to come back to the real word; instead, they use another screen, whether wirelessly or antenna, to see reality.

Beyond FullDiving
During the Alicization arc, a new technology is hinted at which is called Brain Machine Interface, or BMI for short, where the mind is accelerated to x times the normal, giving the person the ability to perform processing x times faster in less time. The BMI uses a different FullDive technique. It starts with «Soul Translation». An example the Kirito uses to explain this complexity is of the brain: the synapse is the sole transmitter between neurons, and then goes into a theory: Quantam brain dynamics, which is like the cell frame to support its structure, like a skull. However, it is in a shape of a tube, which has a light particle, or evanescent photon, a quantum. The collection of photons in the computer, is called «Fluctuating Light», shortened to «Fluctlight». The «Soul Translator» translate «Fluctlight», or the words humans understand and write out the information into a form that could be read.

Usage
To use Nerve Gear and AmuSphere, the player places the game console over the head. Then, the player will lay down in a comfortable position. After, the helmet-like game will activate through the initiation words «Link Start».