Design of Bio Signal Sensors and Signal Conditioning Circuits

Abstract

Many physiological disorders such as Amyotrophic
Lateral Sclerosis (ALS) or injuries such as high-level spinal cord
injury can disrupt the communication path between the brain and the
body. People with severe motor disabilities may lose all voluntary
muscle control. The disabled people with the above mentioned
problems are forced to accept a reduced quality of life which may
result in dependence on caretakers. To deal with these problems,
sophisticated design of equipments for data acquisition and signal
processing of bio potentials are required. An interface which
communicates between a man and machine can solve this problem to
a great extent. The proposed research presents an advanced manmachine
interface by designing sensors that acquire EEG, EOG and
EMG signals from brain, eyes and muscles respectively.
This paper describes a design and development of a method that
acquires eyeball and eye blink signals .Then the acquired signals are
used in controlling assistive/interfaced devices to help subjects who
are partially paralyzed patients. Thus the application lies in the fact
that the model developed is not limited to the degree of paralysis
which has occurred. The design developed is checked for its validity
and is found to be 90% accurate. The experimentation was done on
partially paralyzed subjects as their eyeball movement and the eye
blink were found to be normal. These eye movements and brainwave
signal acquisition of data can be used to control a number of
interactive devices such as a robot, a GUI or the movement of wheel
chair.