Answer-Which of these helps to diagnose a heart problem?

Electrocardiogram ECG monitors the heartbeat of a person. It measures the changing electric impulse with contraction and expansion of the heart. ECGs obtain the analog signals and then convert them into digital ones. Small sticky sensors electrodes are attached to the chest of patients and their heartbeat is measured. William Einthoven is credited with the invention of ECG in 1895 and was also honored with Nobel prize in 1924 .