| Summary: | 碩士 === 國立成功大學 === 醫學工程研究所 === 89 === Abstract
With rapid development of telecommunication technology in the information age, communication in all aspects has been more frequently and the sciences and technology makes the life of human beings more convenient. In the past two decades, western developed countries have extensively designed and developed various communication-aided assistive technology and devices through electronics, telecommunication, information and computer sciences and technologies for the people with hearing and communication impairments. In Taiwan, unfortunately there is few research and development of domestic communication-aided technology. The purpose of this research was to design a telecommunication–aided system through hand writing and imaging transmission to provide visual substitution to speech hearing in bi-directional communication on real-time for the people of hearing impairments. The system of a stand-alone device, which is easily inserted into general telephones network, provides convenient interpersonal communications on daily activity and independent living for the hearing impaired.
More specifically, the functional design of microprocessor-based system was: (1) alternative hand-writing input/visual image output and visual/tactile sensing as well as augmentative interface substituted to speech hearing functions of the telephone; (2) easily inserting to telephones through operating at regular telecommunication networks and maintaining the general speech hearing/voice communication of telephone system. The hardware and software design include microprocessor AT89C52 IC for system control, touch panel of analog resistance type (8*12cm) for hand-writing input, graphical LCD (128*64 pixel resolution) with driver ADS7843E and A/D converter (8 bits, 125 KHz) for imaging output, Modem and programmable serial receiver/transmitter (URAT 8250/8251) to control Modem and baud rate for transmitting and receiving the imaging signal through RS232 with regular communication protocol of signal enveloping transmission, photo coupler for alarming and RF wireless vibrator through relay for tactile sensing to substitute telephone ringing, large peripheral touch panel and switches with keyboard decoder in serial interface with the system.
The prototype development of telecommunication-aided system has been completed with circuit hardware modules and control software design and implementing a microprocessor to control and process the image of touch panel and LCD and telecommunication in signal transmission, and peripheral devices of RF vibrator and alarm. The image of touch panel from user’s hand writing are initially stored and processed by the microcontroller (RAM-2764 and ROM-AT29C256), and then are displayed on the LCD and transmitted by the Modem control module through regular telecommunication networks to the other receiving side for displaying the imaging information on LCD for bi-directional communication on real-time. Currently, the system testing has been ongoing. The imaging drift, compression, compensation, and scale calibration between the touch panel and LCD have been resolved through software and hardware design by using: (1) interrupt signal, delay time, sample time, band pass filters and lower ripple power supply design for minimized drifts and for image smoothing and exquisite; (2) proportional reduction of the image from touch panel to imaging compression on X- and Y-axis of LCD for completed image display; (3) imaging compensation by smoothing interrupted regions of disconnected line image due to various speeds of hand-writing for image reconstruction on LCD display; and (4) scaling methods to enlarge or reduce or translate the touch panel image for appropriate output display on LCD. The image has been transmitted through Modem with 19,200baud rate with serial receiving and transmitting controller UART8250/8251 trough RS232.
Future developments are recommended to use a DSP-based mircoprocessor to enhance mathematical computation, a graphical LCD with better resolution, an ADSL Modem to transmit voice and digital signals in real time simultaneously. Hopefully, this will provide domestically a better telecommunication assistive device to improve the quality of life for the native people with hearing impairments.
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