ECG MACHINE

   An Electrocardiogram, or ECG machine is a simple test that can be used to monitor the heart rhythm and electrical activity of the heart. Electrodes are attached to the skin are used to detect the electrical activity of the heart each time it beats. These signals are recorded by ECG machine and are looked at by a doctor to see whether they're unusual.

The heart generates electrical signal to contract. Cells within the heart can depolarize and repolarize and this process generates electrical energy. The electrical signal in the heart starts at the Sinoatrial node, which stimulates the atria to contract. The signal then travels to the Artioventricular node, followed by the bundle of His, and then through the Purkenje network, which stimulates to contract. When the ventricles are being stimulated to contract, the atria are repolarizing. The electrical signal is called an Electrocardiogram.

The first little upward notch of the ECG wave is called the P wave which indicates that the atria are contacting to pump blood. The next part of the ECG is a short downward  section connected to a tall upward section. The part is called the QRS complex. When the bundle of His fires, the ventricles contract to pump blood. The next upward curve is called  the T-wave which indicated the resting period of the ventricles.

HOW IT WORKS

The electrical activity is picked up by means of electrodes placed on the skin. The signal is amplified, processed whether necessary and then ECG tracings displayed and printed. Some ECG machines also provide preliminary interpretation of ECG recordings. There are 12 different types of recording displayed depending upon the points from where the recordings are taken. Care must be taken to make the electrode sites clean of dirt before applying electrode jelly. Most problems occur with the patient cables or electrodes.