Satoshi Ohtsuka

Helen Keller Phone—a communication system for deaf-blind people using Body-Braille and Skype

We introduce and demonstrate the “Helen Keller Phone” system, which enables deaf-blind people to communicate with each other without any support person and talk over the telephone for free with Skype. All communication is done via Body-Braille and is analogous to audio chat communication by non-disabled people. Real-time conversation using Braille instead of audio signals is possible and would dramatically improve deaf-blind peoples quality of life. The Body-Braille system, which presents one Braille cell using six micro vibrators, has been introduced twice in previous CCNCs. This time we will present newly developed equipment which is very small and portable and includes a new presentation method for Braille cells using only two vibrators, called the “two point system”. This new equipment makes portable use possible. We will demonstrate Braille-based communication through Skype, where one user is at home, the other is on the road.

Introduction of a wireless Body-Braille device and a self-learning system

Body-Braille is a mechanism for presenting one Braille cell using micro-vibrators on any part of the body. One application of Body-Braille is the Helen Keller Phone system which is a communication system for deaf-blind people. It is currently in the commercial stage. Since it is expected that users of Body-Braille will increase in number, a self-learning system for Body-Braille is required. Moreover, such a self-learning system must be easy for deaf-blind users to use. In this paper, we describe a wireless device which we have developed for this purpose and details of a self-learning system for Body-Braille. In order to test the system, we performed an experiment in which 14 subjects recognized Body-braille patterns in the first stage of self-learning. The recognition rate was 74.1%. However, post-experiment interviews revealed a keystroke issue that if corrected, would yield a 92.0% recognition rate.

Analysis of vibration characteristics for Body-Braille reading accuracy

We have developed Body-Braille as an information transmission support tool for Deaf-Blind people. In this paper, improving the readability of Body-Braille is the goal. We investigated the optimal characteristics through two experiments. One is the reading of Body-Braille when produced by three types of motors, which are different in amplitude and frequency. The other is the reading of Body-Braille while changing the frequency with a fixed amplitude. As a result of the experiments, we revealed that the readability was influenced by both amplitude and frequency of the vibrator. Moreover we found that the optimal frequency band of the vibrator was in the range of 70Hz to 100Hz.

The Development of a Music Presentation System by Two Vibrators

We have been developing the Body-Braille system, which transmits Braille characters to disabled people through vibrations on any part of the body. Five years ago, we began working on music applications of this. Using 9 micro vibrators, any melody with a sound range less than 2 octaves can be expressed by vibration. Last year, we developed the music presentation system using only two vibrators. Using special equipment (Pocket-Body braille, Pocket-Bbrll), we performed two experiments and obtained successful results for applying a small number of vibrations to music expression. The details of the system to present music tone by vibration and the results of the experiment are described.

A New Game Device Using Body-Braille for Visually Impaired People

During the last five years, we have been developing the Body-Braille system which uses 6 vibration motors corresponding to the units of Braille. Disabled people can wear this system and sense Braille characters by vibration patterns on any part of the body. We have performed several experiments in which disabled people could get needed support for daily life through Body-Braille. Since we are developing a new type of equipment, we chose to make one of its main applications a game. Our new equipment is so small that it is very easy to carry it anywhere, such as on a train. Disabled people can play a game using the equipment while traveling around. The software of the game application employs a table based structure so that anyone can create a new game application with very little programming work. As a result, we have successfully developed the software for game creation.

Alternative vibration presentation methods for the two-point Body-Braille system

We developed Body-Braille as an information transmission support tool for the deaf-blind using vibrations. In our previous system, a motor was used to generate vibrations. In this study, a vibration speaker was used in an attempt to improve readability. We investigated improvements in the rate of correct answers recorded by participants when using different frequencies, amplitudes, and presentation methods. The chosen parameters were appropriate for the three-sequence vibrations used in the two-point Body-Braille system. Our goal was to identify the parameters which the participants found most natural. A correct answer rate of 85% was achieved even with participants who had never experienced the two-point Body-Braille system.

Introduction of new body-braille devices and applications

In this paper, two new Body-Braille devices are described. After the Body-Braille system and its current development status is explained, first, a new device for Braille-based real-time communication over internet (via Skype) is introduced and second, a new device for autonomous learning, which adopts wireless communication, is explained. The former is already developed and being used in the field test stage; the latter one is being developed now.

The Study of a New Actuator for a Two-Point Body-Braille System

We have been studying the Body-Braille system that transmits Braille characters to disabled people through vibrations on any part of the body. Two years ago, we began to use a SMA (Shape Memory Alloy) device instead of a micro-vibrator. As a result, several advantages were obtained such as smaller equipment size, high resolution transmission, and low power consumption. This year, we developed test equipment for the SMA device which can supply flexible PWM (Pulse Width Modulation) parameters and performed several tests for Braille reading. The test results reveal several possibilities for using a SMA device as a communication channel.

A vibration watch using a mobile phone for visually impaired people

We have developed a vibration watch on a mobile phone for visually impaired people. This watch has some merits: It operates on a mobile phone which many people are always carrying. It does not have to adjust the time because it uses the time function of the mobile phone which is adjusted automatically. In this paper, first we decided the characteristic of the vibration watch. Next we did a experiment which recognizes the number of times of vibration in order to show the time. We found it was difficult for subjects to recognize five vibration or more. Using a long vibration which means 5 times, we were able to shorten the oscillating interval which can recognize the number of times of vibration. Finaly we constituted the vibration watch on a mobile phone and we had confirmed that the watch function operated.