The Development Of Home Environmental Control And Healthcare System For Disabled People

Environmental control unit is a kind of mechanical and electronic equipment specially designed for severely disabled people, helping users to control various appliances in the house. Many approaches have been used in the environmental control unit, such as sip-and-puff switch, joystick, microphone and infrared beam helmet, etc. Based on the study o all these above, the author proposed two kinds of effective methods: one is brain-computer interface (BCI) technology via EEG signal, the other is speech recognition via throat vibration wave.BCI system identifies people's intentions by discriminating different EEG signals, which are evoked by visual stimulation with different frequencies. It consists of EEG signal amplifier, data acquisition, DSP module and executive unit. The following functions are implemented in a portable control box: to turn on/off of electrical devices, to learn, store and transmit the infrared code of remotely controlled devices such as television and air-condition, and to make a telephone call and playback the pre-restored voice. The clinical trial proves that the whole BCI system is of high performance in helping disabled person to control home appliances.The speech recognition system uses the skin vibration signal directly gathered from the throat microphone instead of standard microphone. Throat microphone is highly immune to environmental noise because of its close contact with the throat skin. This paper combines standard (air-conductive voice) and throat microphone (non-air conductive voice) for robust speech recognition. Computer testing results indicate that it is of fairly good capability in recognizing isolated words.In addition, a healthcare system based on gasbag sensor is also developed. The gasbag sensor is putted under the user's bed to sense the tiny vibrancy of body. A program in the computer processes the signal from gasbag sensor, within which separates the ballistocardiogram and the breath wave, and accurately measures out the instantaneous heart rate and breath interval respectively.