X-rays were discovered accidentally by the Germany Physicist William Roentgen in 1895, while experimenting with electron beams in a gas discharge tube. He discovered that a screen in the laboratory started glowing when the electron tube … Read More
Diagnostic techniques are investigations and tests performed on patients with the intention to identify the cause of illness. The ultrasound is sonic energy at frequencies above the audible range. The most widely used applications of ultrasound in diagnostic medicine involve … Read More
Electrooculogram is an electrophysiological monitoring method to record electrical activity of the eyeball. It is a test to measure the electrical response of the light sensitive cells (rods and cones) and motor nerve components of the eye.
Its main applications … Read More
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 … Read More
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 … Read More
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 … Read More
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 … Read More
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 … Read More
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:
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 … Read More
