Technology

The FSRS is based on the collaborative research by Tachi laboratory in the University of Tokyo and EyePlusPlus, Inc. The following is a synopsis of the technologies that are used in the system.

The concept:

Sensory Substitution

Through blindness, a person loses one of the 5 senses, and in this world many would say the primary sense. The concept behind the FSRS is to take that visual information that the person can no longer understand through their eyes and present it in a different way. The FSRS translates visual information to tactile information presented on the forehead. The user is trained to understand and use that information as visual information, without need for eyesight.

The application:

Forehead Stimulation

Though sensory substitution through electrical stimulation was proposed in the 1960s, technology has simply been unable to meet the concept in an attractive way until now. The FSRS device is easy to put on and take off, the CPU is highly portable, the forehead (and face in general) is sensitive to tactile stimulation, and coordinate system transference to the brain is much easier here than other parts of the body.

Image Processing

Visual images captured by the camera are converted to tactile information through two processes. The first is a spatial outline extraction to enhance edges. The second is a temporal band-pass filtering to enhance time-varying information. Simply put, this is the function of an actual retina. The FSRS imitates pre-process in the real visual system, only the result is processed tactily on the forehead rather than with the eyes.

Technical References:

1.     Kajimoto, Kawakami, Maeda, Tachi, "Tactile Feeling Display using Functional Electrical Stimulation," Ninth International Conference on Artificial reality and Telexistence, 1999.

2.     Kajimoto, Kawakami, Tachi, "Optimal design method for selective nerve stimulation and its application to electrocutaneous display," Tenth Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, pp.303-310, Mar 2002.