A system and method for powering a wireless sensor device are disclosed. In a first aspect, the wireless sensor device comprises at least two electrodes configured to be attached to a body and at least two leads coupled to the at least two electrodes. The wireless sensor device also includes a system on chip (SoC) coupled to the at least two leads and a portable power source (Vbatt) coupled to the SoC. When the at least two electrodes are attached to the body, a difference in resistance is measured between the at least two leads by the SoC and the difference in resistance is utilized by the SoC to enable the portable power source to activate the wireless sensor device.
