Author: John Mulindi
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Electromyogram (EMG)
The contraction of the skeletal muscle results in the generation of action potentials in the individual muscle fibres, a record of which is known as electromyogram. This activity is similar to that observed in the cardiac muscle, but in the skeletal muscle, repolarization takes place much more rapidly, the action potential lasting only a few…
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Electroencephalogram (EEG)
The brain generates rhythmically potentials which originate in the individual neurons of the brain. These potentials get summated as millions of cell discharge synchronously and appear as a surface waveform, the recording of which is known as the electroencephalogram. The neurons like other cells of the body are electrically polarized at rest. The interior of…
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Electrocardiogram (ECG)
The recording of the electrical activity associated with the functioning of the heart is known as Electrocardiogram. ECG is quasi-periodical, rhythmically repeating signal synchronized by the function of the heart; which acts as a generator of bioelectric events. This generated signal can be described by means of a simple electric dipole (pole consisting of a…
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Types of Bioelectrodes
Introduction Bioelectric events have to be picked up from the surface of the body before they can be put to the amplifier for subsequent record or display. This is done by use of electrodes. The potentials produced at different points are measured by placing electrodes at various points on the body. They carry the currents…
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How are the Potentials in the Body generated?
In the 18th Century, Galvani demonstrated using microelectrodes that there is a potential difference between the outside and the inside of a cell, or a potential difference exists across the membrane of a cell. The inside of a cell has a negative charge and the outside has a positive charge, the potential difference being around…
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Sources of Biomedical Signals
Biomedical signals/physiological signals are those signals (phenomenon that conveys information) which are used primarily for extracting information on a biological system under investigation. Our body produces various physiological signals. The accessibility to these signals is important because these signals: All physiological signals can grouped as: A transducer converts a physical signal into an electrical output.…
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Key Points to Note when using a Biomedical Instrumentation System
In most of the medical instrumentation systems, some calibration is necessary at regular intervals during their operation. The calibration signal is applied to the sensor input or as early in the signal processing chain as possible. In many measurement applications in the medical field, some form of stimulus or energy is given to the patient…
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The Introduction to Biomedical Instrumentation
Introduction Biomedical Instrumentation deals with the measurement and analysis of current or voltage signals from different parts of the body. The human body generates a variety of voltages which are usually very small. Biomedical instrumentation helps medical personnel or physicians to make a better diagnose of the problem in a patient and provide the appropriate…