sensitive instrument which includes the following main parts: 1) sensing electrodes, which are attached to the skin of the patient to pick up the potential differences that arise during excitation of the heart muscle, and lead wires; 2) amplifiers, which amplify the voltage of electromotive force (1-2 mV) to the level that can be recorded;
3) galvanometer to measure the voltage; 4) rec-order printer, including a traction mechanism and a time marker; 5) isolated power supply.
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Figure 6 – Scheme of the one-lined electro-cardiograph
Depolarization potentials that arise during the excitation of the heart tissue are sensed by the electrodes attached to the patience skin. Than impulse conducts to the amplify part of electrocardiograph and amplified 600 times. After that electromotive force registers by galvanometer, and recording device shows a different curves on a moving heat-sensitive paper.
Figure 7 – ECG registration
Recording rules:
1. The patient must lie down and relax.
2. Connect up the limb electrodes, making. Certain, that they are applied to the correct limb.
3. Calibrate the record with the 1 mV signal.
4. Record the six standard leads three or four complexes are sufficient for each.
