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Showing posts from April, 2024

Light and its properties

The basic definition of Light: Light is a form of energy that produces the sensation of vision in the eye by which we can see objects. There are some facts about light as follows: 1. Lightwave moves along a straight line path. 2. Light waves can travel through vacuum and medium both. 3. Light is an electromagnetic wave. 4. A light wave is the transverse wave in nature. 5. Light can be dispersed. Besides these facts, light also shows the phenomenon of interference, diffraction, polarisation photoelectric effect, etc. To explain the above facts, many principles have been given from time to time, e.g., Newton's corpuscular theory, Huygen wave theory, Maxwell's principle of electromagnetic wave, Planck's quantum principle, dual nature of light, etc.

Origin of Biomedical Signals

The biomedical signals differ from other signals only in terms of the application — signals that are used in the biomedical field. As such, biomedical signals are produced from a variety of sources. The following is a brief description of these sources: 1. Bioelectric signals:  The bioelectric signal is unique to biomedical systems. It is produced by nerve cells and muscle cells. It is produced due to the membrane potential, which under certain conditions may be excited to generate an action potential. In single-cell measurements, the specific microelectrodes are used as sensors, and the action potential itself is considered as the biomedical signal. In more gross measurements, the surface electrodes are used as sensors, and the electric field generated by the action of many cells, distributed in the electrode’s vicinity, constitutes the bioelectric signal. Bioelectric signals are probably the foremost biosignals. The fact that most biosystems use excitable cells makes it possible,