Diagnostic Instruments used in Medical Science

1. Electrocardiograph (ECG)

Electrocardiograph (ECG) is an instrument used to diagnose heart disorders. It detects the changes in electrical potential generated by contraction of heart muscles. Each time the heart beats, it produces electrical currents. These currents are responsible for the rate and pattern of contraction of the heart. An electrocardiograph picks up these currents and records them on paper. The electrocardiograph may be connected to a printer, which prints the record. This record is called an electrocardiogram, often abbreviated to ECG. The electrocardiograph may also be conneted to an oscilloscope, an instrument that displays the currents on a TV-type screen. An electrocardiograph contains amplifying and recording equipment. Wires run from the machine to electrodes-strips of metal that conduct electricity.

2. Electroencephalograph (EEG)

Electroencephalograph is an instrument used to measure and record the electrical voltages produced by neurons in the brain. A recording of this electrical activity is called an Electroencephalograph. EEG is used to diagnose epilepsy, encephalities, dimentia and brain tumour. Doctors and neuroscientists use the Electroencephalograph to study normal brain activity, as well as abnormal brain states that are caused by injury, tumour, infection or even death. To record an Electroencephalograph, medical personnel attach electrodes from the Electroencephalograph to the patient's scalp. Hans Berger, a German psychiatrist invented the first Electroencephalograph in 1929 to measure the rhythmical electrical activity of the human brain.

3. Electromyography (EMG)

The process of measuring and recording a muscle's action potential is called electromyography. An electromyography equipment is used to take an EMG, and the resulting record is called an electromyogram. An EMG can be used to analyze the electrical activity of muscle cells both during exercise and during rest. The EMG potentials that are measured fall between 50 µ and 30 millivolts. There are primarily two types of EMG measurements. Surface electrodes are used in the first procedure, and needle electrodes are used in the second. While needle electrodes are used to observe the electrical activity of a limited number of fibers, surface EMG electrodes are used to monitor the electrical activity of muscles in general.

4. Auto Analyser

These are computerised instruments used for biochemical identification of various body fluids such as urea, cholesterol, glucose, protein.

5. Otoscope

It is an instrument used for examining the outer ear and ear drum.