Device for obtaining ECG

Present disclosure relates to a device for obtaining ECG. The device includes a first electrode, a second electrode and a processor. The first electrode and the second electrode are connected to a first side and a second side of the processor respectively. When the first electrode and the second electrode connect to two of the three limbs of a user respectively, the processor detects three sets of voltage variations between each two of the three limbs and provides first to third voltages by calculating the three sets of voltage variations. When the first electrode connects to one of the user's limbs and the second electrode connects to six parts around the user's chest respectively, the processor detects six sets of voltage variations between one of the limbs and one of the six parts around the user's chest. The processor provides fourth to ninth voltages by calculating another six sets of voltage variations. A twelve leads ECG may be provided by a calculation conducted from the first to ninth voltages.