A defibrillator device is provided. The defibrillator device includes a first electrode, a second electrode, a readout module, a USB interface, a voltage converter and a stimulation module. When the first and second electrodes contact the chest of a patient, the readout module obtains a physiologic rhythm signal of the patient and provides a heart rhythm signal according to the first physiologic rhythm signal. According to a first voltage from a portable electronic device, the voltage converter generates a second voltage when the first USB interface is coupled to the portable electronic device, wherein the second voltage is larger than the first voltage. When the physiologic rhythm signal indicates that cardiac arrhythmia is present in the patient, the stimulation module provides an electric shock energy to the chest of the patient via the first and second electrodes according to the second voltage.
