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Contents
Study Objectives
Introduction
We as a source of signals
Biomedical Signal Analysis: Basic Concepts.
Examples of Signals that we are the source of
We as a sink of signals
Summary
Study Objectives
Our major objectives are to;Have a look into the types of signals we are the
source of.Have a glance on the signals that we are
immersed in.Study the Nature, Features and Characteristics
of some exemplary signals.Understand the basics of biological signal
analysis.
Introduction
Definition:
Signal: any physical quantity that varies as a function of an independent variable and conveys an information. The Independent variable is usually time but may be space, distance, ...
Introduction…
We are living in a sea of signals.
We act as a medium for the transmission of different kinds of signals. Even we’re good conductors for some kinds of signals.
The signals are so small in magnitude- and need some kind of amplification and processing for detection.
Introduction…
As we are living in the universe we are exposed to the signals or stimulations from the environment.
So as we are a source we are a sink for signals, too.
Understanding of these signals; their nature origin, and types will help us in explaining and identifying pathological conditions of the human body.
We as a source of signals
In case of accidents, we rush to touch certain parts of a person to detect the signals of life.
This shows how important signals are.
We as a source…
How they are produced?Our body is an integrated system with all of its
parts in constant communication with each other and interdependent upon one another.
Because of the different and complex physiological activities in our body we emanate many types of signals.
We as a Source…
Definition: Biosignal:Signals generated during physiological process in
human body.It is a summarizing term for all kinds of signals that
can be measured and monitored from biological beings in human body.
Include both electrical and non-electrical signals being generated in human body.
Biomedical signal is used to refer various types of bio-signals that can be picked up from different part of our body and are used in the medical fields.
Biomedical Signal Analysis: Basic Concepts
Biomedical signal analysis deals with analyzing signals generated by various physiological processes in the human body. It may include several processes in step flow.
These signals could be electrical, or can be non-electrical. Here, in biomedical signal analysis all signals are converted in to electrical signals…
Biomedical Signal Analysis: Basic Concepts
Biological signals: types and sources
Biological Signals…
Biological Signals…
Biological Signals…
Some exemplary signals
There are many signals that are picked up from our body for diagnosis using specialized biomedical equipments.
Let us see very few examples;
Some exemplary signals
Electromyograph(EMG)is an electrical measure of skeletal muscle activity.human skeletal muscle is excited by motor
nuerons.When a muscle is excited, an action potential
propagates from the one end to the other ends of the muscle fibers.
EMG…
Simplified model of the nature of the EMG signal
Some exemplary…
Electroencephalograph(EEG)
is the electrical measure of the sum/average neural activities in our brain.
EEG signals are extremely small voltage signals (nearly 200 micro volts or less).
Highly conductive electrodes are used to collect the signals.
Some exemplary…
EEG Setup - General
Some exemplary…
Aura
The aura is a field of energy that surrounds people and other living things. it reflects the energy of the spirit in that body.
This energy extends about two to four inches around the body and is usually a light or pastel shade.
Its colours, textures and patterns reveal much information about physical, emotional, mental and
spiritual states.
Some exemplary…
An aura is like a thumbprint; it is completely individual and expresses who you really are.
Different studies are being held how to image it and apply it for medical purposes.
We as a Sink of Signals
The human body is exposed to different signals from its surrounding or environment.
Our body is an extraordinary and complicated system that automatically detects and responds to dramatic environmental changes that surround it.
Signals from the environment that are all around us that tell our bodies about the external and internal environment are called Stimuli.
We as a Sink…
These signals can be applied to us deliberately or …
We can sense and react for most of these signals.
Our sensory organs are the primary components that create the interface between the environment & our CNS.
At any given moment, in any given environment, there is simply too much to take in all at once.
The stimulus that we choose to attend to, or focus on is termed as the Attended Stimuli.
We as a Sink…
Definition: Sensation: The process by which a stimulated receptor creates a pattern of neural messages that represent the stimulus in the brain.
Yet we humans do have our sensory limitations.
We as a Sink…
Perception: is a mental process that elaborates and assigns meaning to the incoming sensory patterns.
Thus perception creates the interpretation of sensation.
We as a Sink…
What is the weakest stimulus an organism can detect? How soft can a music be played and still be heard?
The minimum amount of physical energy needed to produce a sensory experience. This is called Absolute Threshold.
This threshold varies from one person to another.
We are obliged to use other devices to sense/detect the stimuli that are below the this threshold value.
We as a Sink…
Approximate thresholds
We as a Sink…
Definition:Sensory adaptation: loss of responsiveness in receptor
cells after stimulations has remained unchanged for a while.
Thus our sense organs are change detectors.
We as a Sink…
Fundamental features of the human senses
Summary
It is because of the signals that we produce that we are able to get medications for our illnesses.
It is because of our ability to sense signals that we become able to;
know tasty foodlocate mates seek shelter recognize our friends. And so
on…
Signals are reasons for our existence in
life!
Thank you for your attention!
