CARDIAC RITHM

The design and construction of electronic circuits to solve practical problems is an essential technique in the fields of electronic engineering and computer engineering.

At every heartbeat the arterial blood pressure raises (systolic period) and the dimension of the tips of the fingers slightly increases, while the higher oxygenation causes the decrease of the optical density of the skin tissue.

During the cardiac relaxation period (diastolic period) the pressure decreases, the density increases and the physical dimension of the tips of the fingers decreases.

Since these cyclical variations follow the cardiac rhythm, they can be used to measure the frequency of the peripheral pulsations.