2001 Conference Proceedings

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Development of New Passive Braille Method and an Information Receiving Terminal for Visually Impaired Person

Tadahiro Sakai, Tatsuya Ishihara , Takayuki Ito and Haruo Isono
E-mail: sakaita@strl.nhk.or.jp 
NHK Science and Technical Research Laboratories
1-10-11 Kinuta, Setagaya-ku, Tokyo, 157-8510,Japan

Abstract

We have developed an integrated information receiving terminal to enable visually impaired persons to easily access such information as multimedia news and emergency disaster reports. The new terminal is capable of conveying information such as text broadcasts, ISDB, emergency news and text data from floppy disk. It also has a remote communication function for persons with both visual and hearing impairments. Information output devices available for the integrated receiving terminal currently include a conventional braille display unit, a speech synthesis device, and a 6-finger braille terminal. The 6-finger terminal uses a new braille presentation method, distributing one of the six points which make up the conventional braille character display to each of six fingertips, which is easier for users and particularly braille novices to read. Users can select output devices that suit their own needs from among those available.

1. Introduction

Everyone should have access to the rich and diverse information that will be readily available through digital broadcasting as well as to emergency news in the event of natural disasters and the like. Our research team has studied a 6-finger braille method that makes it easier for the vision/hearing-impaired and particularly braille novices to read braille. The ultimate aim of this method is to allow anybody to read braille. Nobody should be isolated from information because of a visual impairment. Using this method, we also have been developing integrated information receiving terminals that make information such as text broadcasts, ISDB (Integrated Service Digital Broadcasting), emergency news, and text data from files in memory more readily available. [1][2]. Moreover, a remote communication function has been developed for persons with both visual and hearing impairments. At present there are few means of remote communication for the vision/hearing-impaired which do not require the intervention of a third party [3]. Remote communication can facilitate two-way participation in a broadcasting program or lower the communication barrier for those with visual and/or hearing difficulties. An outline of these is reported here.

2. 6-finger braille method and 6-finger braille terminal

The 6-finger braille method and presentation by stimulation The 6-finger braille method is a new presentation method in which one of the six points that make up the conventional braille letter display is distributed to each of six fingertips. Therefore, one letter is displayed by stimulation on six fingers. Figure 1 shows the principle of the 6-finger braille method. In the 6-finger braille method, several stimulating elements are assigned to the fingers, with the stimulation being given in such a manner that the perception of apparent motion is produced. Each finger receives a sensation that is traced. With this method, because each braille point is separated, it is easier for the vision-impaired who have lost their sight later in life and who cannot read conventional braille and particularly braille novices to read. And they can learn how to read braille text after a relatively short period of training. Also, the presentation pattern of the 6-finger braille method is similar to conventional "finger braille", which nevertheless is an important means of communication for the vision/hearing-impaired.

Fig. 1 Principle of the 6-finger braille method Outline of 6-finger braille terminal and tactile reading Figure 2 shows the appearance and functions of the braille unit (the 6-finger braille terminal), which uses the 6-finger braille method. It is composed of a tactile-reading control jog, a control key, and braille presentation & input keys. Users can renew letters, change presentation speed or go back one sentence according to the rotation angle of the control jog. Control keys are used to select information or control the state of a conversation, such as providing timely responses, in remote communication. These jog and control keys are located in positions in which users can operate them with each finger on the 6-finger braille presentation keys. The braille presentation keys also function as an input device. Users can input letters like a braille typewriter. A mechanism incorporating electromagnetic solenoid locks is used for toggling between input and output modes. During tactile reading of the data, these input keys are locked to prevent input of new information.

By using this type of 6-finger braille terminal and putting six fingers on the presentation keys and rotating the jog, users can read braille at a speed which suits them. Braille is presented by in a time-sequential manner. Further, data are presented in such a way that there is an interval (a duration of time with no stimulation) after each word in order to prevent a user's perception from diminishing as a result of his tactile sensation becoming accustomed to continuous stimulation such as vibration. When reading the data, a user can choose the more suitable of the following two modes depending on his or her ability to read braille. In the first mode, the display automatically advances to the next letter after a preset time interval. In the second mode, the display advances only after the user acknowledges the previous letter.

Fig. 2 Appearance and functions of the 6-finger braille terminal

3. Configuration of the integrated information receiving terminal for the vision-impaired

System arrangement It is able to access and obtain such text data as text broadcasts, ISDB, emergency news, and text data from files in memory by the developed information receiving terminal. Remote communication via telephone line was also developed. Figure 3 shows the overall arrangement of this receiving terminal and information resources. It is composed of information receivers, input/output devices, and a wearable vibration indicator. A paired system for remote communication and its information resources are shown in this figure.As information output devices for an information receiving terminal, we have prepared a conventional braille display unit, a speech synthesis device, a CRT as well as a 6-finger braille terminal. Users can choose a means that suits their own needs from among these.

The text data from the information resources are shown time-sequentially letter by letter at the 6-finger braille terminal, and line by line at the braille pin display. The voice synthesizer allows the user to choose the type of reading: letter-by-letter reading synchronized with the 6-finger braille operation, or whole-sentence reading. The CRT displays the text data; small letters can be enlarged for those with weak eyesight. The input unit consists of the braille input key on the 6-finger braille terminal, a conventional keyboard, and a microphone. Key words and other data that are used for selecting information or conversation data can be entered via the 6-point input keys on the 6-finger braille terminal and the keyboard.

The mount-type vibrator comprises the receiving part of a small power FM transceiver and a vibration motor. It begins to vibrate to send tactile sensation signals when an emergency broadcast or a telephone call is detected. Different FM frequencies are used for the detection of emergency broadcasts and telephone calls. The vibrator drives its motor at different cycles so that the user can distinguish between these two information sources by the length of the cycles.

Fig. 3 Arrangement and information sources of integrated broadcast receive terminals Access to text broadcasting data Program data received by the text broadcast receiver are filed in the designated memory area according to the genre of the programs. The braille data are first converted into spaced "kana" words from the jumble of kana and kanji characters, and then converted into codes for 6-finger braille output. Next, these braille data are shown at the 6-finger braille terminal and the braille pin display. The programs on the menu are re-classified into two or three layers so that the vision-impaired can select desired programs easily. The following three methods of program selection are available: ‡@ The user chooses the program with the control keys while getting the sequentially displayed data on the menu. ‡A The user directly chooses the program by typing in the corresponding number of the text broadcast program via the input keys. ‡B The user directly chooses the program by typing in the corresponding key word of the text broadcast program via the braille keys.

Conveyance of emergency broadcasts When the emergency broadcast receiver detects an emergency broadcast, the receiver sends a signal to the mount-type vibrator and switches the computer power on. At the same time, the disaster information is automatically prepared for display.

Selection from the ISDB index screen With ISDB, the user can choose programs from an index screen. Items on the ISDB index screen will likely be arranged two-dimensionally via a graphic user interface (GUI). Assuming that users will have access to electronic program guides (EPG) and item tag information along with ISDB programs in the future, we are studying a way to transmit index items along with time-sequential text data. This method would allow the user to choose the program from the menu in much the same way as text broadcasting. More studies will be needed to develop interfaces for existing ISDB receivers.

Remote communication System layout and outline Computers are connected by voice modems in the paired remote communication system shown at Fig. 3. These voice modems can send voices and conversation data at the same time. The entered conversation data that are input by 6-finger braille input keys and a keyboard are sent, letter by letter, via the voice modem. When received, data are sent to the sequential 6-finger braille terminal, braille pin display, voice synthesizer, and display monitor. Thus, as the conversation data are received visually, aurally, and tactually, the user can have a conversation regardless of the type of physical impairment. A real-time conversation is also possible with this system. Conversation protocol and tactile reading of conversation data The conversation protocol is as follows.
  1. The user inputs the telephone number using braille input keys or number keys at the sender sideT.


  2. At the receiver side, a wearable vibration indicator notifies the user of an incoming call. At the sender side , vibration which is similar to call sound of telephone is presented on the 6-finger braille presentation keys.


  3. After the line is connected the send /receive user name, telephone number and conversation mode are displayed.


  4. After the identity of the other party has been confirmed, the CR key is pushed to complete the preparation for the conversation.


  5. One of the parties pushes the SP key to speak.


  6. The speaker inputs the conversation data. The listener is prohibited from using the input key.


  7. When the speaker finishes inputting the conversation data, the ESC key is pushed to return to 4.
Thus, users can have a conversation by alternately becoming the speaker.The 6-finger braille terminal allows the user to choose a suitable mode of conversation from among the following three depending on his or her tactile-reading ability. In the first mode, data input by the speaker are successively presented for a real-time conversation. In the second mode, the data input by the speaker are checked letter by letter and the user can have a real-time conversation. In the third mode, the data input by the speaker are maintained and the listener can choose a suitable tactile reading mode to read the sentence-by-sentence data from the speaker. These conversation modes are in agreement with the tactile reading mode. Also, the send data are stored in the memory for re-reading. Re-reading during a conversation is possible in any of these modes. In the second and third modes, the speaker is prohibited from using the braille keys to input new information until the listener checks and understands the entered data. Fig. 4 shows a protocol of a conversation in real-time mode.

Fig. 4 An example of a conversation protocol (real-time mode) Presenting the state of conversation In communicating with the vision/hearing-impaired, the following factors in addition to the actual conversation should be considered: notification of telephone calls, acquisition of the right to speak, timing of conversation start and end, state of conversation (during re-reading of conversation data, etc.), and a break for giving timely responses, asking questions, and correcting what has been said. These pieces of information can be conveyed by vibrating the braille presentation part of the 6-finger braille terminal; types of vibration here differ from those used for the conversation data. The method we have developed combines the vibration frequency, duration, cycle, and stimulation time differences in a way that resembles the sensation a person feels on his fingers when conversing by "finger braille". To correct what has been said during a conversation, for instance, one of the two parties to the conversation repeatedly moves his fingers right and left on the back of the other's hand. With this 6-finger terminal, these six fingers are driven time-differentially under the stimulating conditions that give rise to the perception of apparent motion.

Evaluation result of remote communication In two cases, both with a visual and hearing impairment and one person with a visual and hearing impairment and one sighted person, participated in the evaluation test. Each of these subjects was able to maintain a conversation fairly well, although there was some room for improvement in the operability of the terminal and the conversation protocol. The response from the vision/hearing-impaired participants was very positive, indicating that the terminal would be an effective communication tool in the event of a disaster.

4. Conclusion

We have reported 6-finger braille method and developed an integrated information receiving terminal to convey information to the vision-impaired and those with both visual and hearing impairments. In future studies, we will evaluate the remote communication functions for the vision/hearing-impaired for further improvements, optimize ways to give stimulation for precise braille reading while increasing the speed of reading for the 6-finger braille method , and study ways to convey ISDB index displays using a GUI environment.

References

[1]Sakai et al.: "Study of New Passive Tactile Braille- Transmission Methods ," ITE, Vol. 52, No. 4, pp. 512-519 (1998) [2] Ishihara et al.: "A Method for ISDB Index Display Selection for the Vision-Impaired," ITE, 10-2 (1998) [3] Kobayashi et al.: "The Possibility and Problems of the Computer- Network Use by the Deaf-Blind", IEICE,ET 97-79 (1997)


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