Human body generates various different signals. Biosignal
can be defined as any signal in living beings that can be
continually measured and monitored. It can be both electrical
and non-electrical signals. Bioelectrical signals can be sensed
by non-invasive method by using skin-surface transducer,
which is commonly used for Electrocardiograph (ECG),
Electromyography (EMG), Electroencephalogram (EEG) and
electrooculogram (EOG) [1]. Both ECG and EOG signals are
bipolar low-frequency signal. The normal range of ECG signal
is 0.05-100Hz having its amplitude ranges from 10μV to 5mV,
whose typical value is 1mV [2]. EOG signal ranges between 15
μV to 200 μV with a frequency range of about 0-30 Hz [3].
Generally the amplitude of the EMG signal ranges from 0-
10mV (peak-to-peak) and its frequency ranges from 0- 500Hz
[4]. The dominant energy in EMG is being in 50-150Hz [4].
The frequency information of those signal is highly useful
for disease diagnosis. Among those signals ECG is very useful
for diagnosis especially for heart related diseases and disorders
such as, cardiovascular disease, pulmonary disease, sudden
cardiac arrest, etc [5]. EMG is used clinically for diagnosis of
neurological and neuromuscular problems. Another important
application of EMG and EOG is human machine interface and
controlling of various devices.
Our research aims to develop a low cost biosignal
acquisition system which is affordable for the people of
developing and under developed country. In our previous
papers, we have developed an ECG data acquisition system and
an ECG monitoring system [6,7]. In this research, we have
modified the system for acquisition of ECG, EOG and EMG
together. This paper presents a prototype biosignal acquisition
system, which is portable, battery powered and it includes
wireless facility. In this system biosignal is transferred by
Bluetooth serial communication and it gives wireless
connectivity up to 9 meter. The equipment used in this system
consumes low power and this system is battery powered. For
this it can be used during load shedding and on those remote
areas where electricity have not reached